Argumentics

Reconstructing the Chinese Room (I)

2012-01-27T18:16:00.000+02:00

Historical background*

1936

Alan Turing publishes a paper entitled “On computable numbers, with an application to the Entscheidungsproblem”. The problem referred to in the title is one posed by David Hilbert (don’t know if the problem is from those legendary 100 posed at the international colloquium…): is there any effective (i.e. mechanical & finite) way of determining, of any given statement in a formal system, whether or not it is provable in that system? Because he had set out to show that there is no such thing, i.e. that mathematics is undecidable, Alan Turing needed a precise definition of what “effective & finite” meant in this context. Turing came up with this: there is an “effective & finite” way of calculating the values of a mathematical function if it can be processed by a ‘computer’ – at that time the meaning of the term was that of ‘a human who computes’ – which he called the Turing machine. This was the first description of a very basic computer and its computer program.

Along with the description of this machine came the thesis (later dubbed ‘Turing’s theorem’) that the outputs of any one of these machines can be written as inputs to other Turing machines ad infinitum. Although it is impossible to construct and/or operate with such machines, the idea opened up an inspiration for those who believed the prototype of unlimited storage and perfect reliability.

But even assuming some functions are undecidable, what is this sub-set of decidable functions and how is it to be identified? The American logician Alonzo Church had posited in late 1933’s the idea that this set could be identified with the notion of recursive functions (a concept mathematically precise enough since it relied on the (by then) well known concept of lambda-calculus).

The Church-Turing thesis was born out of the unification of these two views. The set of recursive definitions, those functions which are computable by Turing machines, is the same as the set of functions which can be computed by any effective, mechanical, finite etc. method.

1950

Turing publishes “Computing Machinery and Intelligence” in which he recasts the can-computers-think-question into the form of a game: we can speak of it as intelligent if it renders impossible for a human “interrogator” to tell whether the output (coming from it) is that of a machine or a human mind.

Many attacked the psychological assumptions behind this test, the Turing test. [Rather preoccupied about gluing one’s surname to each of one’s productions, isn’t he? I wouldn’t be surprised if I found out colleagues started calling him Turing’s body…] It was accused of being too behavioristic – that is, assuming that the meaning of the statements about one’s psychological states can be reduced to statements about his bodily motion. It was also accused of being too operational – the epistemological view that the concepts of science (“intelligence”, here) should be defined “in terms of” the number of operations we need to apply in order to verify them

1960s

The idea of a Turing test, together with the criticisms it received, was taken over by the American philosopher Hilary Putnam who stated what came to be known as the functionalist view of the mind. According to this view, mentality is a matter of functioning not of substance. In other words, it doesn’t matter what the mind is made of, what matters is what it does, how it works and what is capacities are. By “to matter”, here, Putnam meant mostly “to be able to speak meaningfully of”. Mental concepts, in other words, are functional concepts.

But then, if this is the case, then whatever simulates mental phenomena amounts to duplicating them – since all that there is to mental phenomena is their functioning. There’s no reason, Putnam implies, not to credit computers running appropriate programs with mentality. In fact, both minds and computer can be described in two ways: by referring to their hardware (this impulse passed from there to there, thereby enabling this and that and that causing such-and-such which gave a certain output) or to their software (the computer calculated 2+2). Hardware/software – brain/mind: the analogy worked perfectly.

Of course, many contested this view as well. It was primarily the serial workings of the Turing test that troubled scientists. We know that the mind is capable of more than one state at one time (at least a state and its introspective duplicate). A Turing machine, however, can only be in one state at a time – even if its program can process a collection of series.

Another, more profound, criticism to this idea was the point that psychological states are incompletely described if one doesn’t take into consideration their causal connection with sensory or other behavioral outputs.

Artificial Intelligence: Strong & Weak

Starting mid-1950s, but producing observable results only some ten years later, the artificial intelligence research programme, if one can speak of such a unitary entity, started by looking into the connections between neurons and symbols. First concerned with the classic task of computing, AI researcher were gradually interested in games (chess, guess-games) and then further in what might be called “understanding” (language, planning, learning etc.)

According to the view they held as to the aim of this programme, two versions of AI have been distinguished. The Weak AI is committed merely understanding human psychological phenomena and trying to replicate these so that a computer can produce the same results without the implication that such a computer would thereby have the psychological states. The more radical view, known as Strong AI, is committed to the idea that such a program would genuinely have those psychological states (remember “functionalism”?). As Searle later put it, that such a program would “have a mind in the same sense you and I have”.

[What seems apparent to me is that these “versions” of AI are different neither in their empirical commitments nor in their theoretical scope. They are methodologically different; that is, they are different in what they take as good or bad method. For one, it is cool to say that the super-computer is having this or that psychological state. For the other, it is not. I also think that the methodological import of these versions can be easily omitted. One of Preston (2002) quotes is an example of how this can be done:

Searle, on the other hand, claims to have found an argument that undercuts the idea that electronic digital computer can be said to exhibit any of the contested psychological capacities purely in virtue of their programs. Philosophers certainly have no insight into what technical tasks programmed machines might be able to perform, or when. But they can have a say about how it makes sense to characterize the abilities in question. (p. 16)

So far, from the italics above, it is clear (I think) that the bone of contention is methodological. Whether concerned with the property of terms such as “psychological states” or with how is neat and profitable to act as a scientist, they are prescriptive standpoints. Preston, however, seems to conclude the paragraph by judging CRA with having made a descriptive point about what can and cannot be the case (as opposed to “be said to be the case”). He continues:

Like anyone else they may, by using thought experiments for example, establish or refute thesis about what is logically possible.

______

*The series “Reconstructing the Chinese Room” follows some of the articles in:

Preston, J. & Bishop, M. (2002). Views into the Chinese Room: New essays on Searle and artificial intelligence. Oxford: Clarendon Press.

The first three posts will follow:

Preston, J. (2002). Introduction. In Preston, J & Bishop, M. Views into the Chinese Room: New essays on Searle and artificial intelligence, pp. 1-51. Oxford: Clarendon Press

An answer to the gap problem (?)

2012-01-25T15:24:00.004+02:00

Brown, J. (2011). Thought experiments, intuitions and philosophical evidence. Dialectica, 65(4), 493-516.

The paper starts as follows: “What is the nature of evidence provided by thought experiments in philosophy?” What is surprising, then, in view of this undertaking, is that none of the towering literature on this matter is quoted or used. Unfortunately, instead of providing a fresh approach on this old chestnut, the conclusions supported in the paper are rather unsophisticated.

Brown identifies the problem as follows:

the psychological proposition that it seems to me as if the Gettier subject has a non-knowledge justified true belief is not in itself a counterexample to the JTB theory of knowledge. A genuine counterexample would be a case of justified true belief which is not knowledge (Brown, 2011, p. 500)

So yes, the old intuition-pumps criticism put forward by Daniel Dennett. If thought experiments are based merely on “what one would say” or “what one would feel” or “what one would accept” in the depicted scenario, how can we use thought experiments to support those solid, difficult, objective theories? Using Brown’s terminology, and putting it a bit crudely, how can psychological facts support non-psychological propositions? The assumption underpinning the relevance of this question is that there is a gap (of the subjective/objective kind).

there is a gap between one’s perceptual evidence and what it is taken to be evidence for, in the sense that the proposition that one is having an experience as of p does not entail that p is the case.

Brown diligently considers many views and viewpoints on this matter and some other ones more or less related. She spends a lot of time with the similar problem of perception (how can perception justify theoretical knowledge? etc.)

Finally, her answer is this. I’m quoting it because I don’t understand it.

one could close this apparent gap by appeal to an externalist approach to justification and/or knowledge. Suppose that whenever one has such an experience, one forms an appropriately related belief. For instance, that when one has an experience as of a large barking dog in front of one, one forms the belief that there is a large barking dog in front of one. On an externalist approach to justification, such as reliabilism, as long as the appropriate external relations hold, the beliefs so formed are justified.

One might hope to apply this solution to the gap problem in the case of perception to the gap problem facing the psychological view of thought-experiment evidence. Suppose that, in fact, the method of forming beliefs about the nonpsychological subject matter of philosophy on the basis of the relevant psychological propositions is reliable. Combining this supposition with a reliabilist approach to justification has the result that beliefs formed in this manner are justified (p. 513)

I honestly do not see what this “combination” means. I understand she is saying this: “Well, remember how subjective propositions can support subjective propositions? Take that, and apply it to our situation, where subjective propositions must support objective ones and say that the appropriate external relations must hold”. But how is this an answer to the problem? One should immediately respond: “Well sure, there must be some extra conditions applying to this step since we know that sometimes subjective/psychological data is misleading and leads to unjustified objective/non-psychological data. We know that. We know that not all of those inferences are justified and we know that the ones that are justified are as such in virtue of the criteria. But the question here concerns precisely these criteria. It is no news nor solution to say – ‘Well, you see, some criteria must hold, criteria concerining the passing from the subjective to the objective’”.

All in all, I guess, this boils down to answering the question of expertise: When is appeal to expertise to be trusted? Because, in thought-experiments that appeal to intuitions – if there are such things, and I think there are – it is the philosopher’s claim to his expertise on one’s intuition that functions as argument.

Unfortunately, it might turn out that no universal answer is possible and that the criteria are highly field-dependent.

A TE against JTB

2012-01-23T13:35:00.002+02:00

The original Gettier-problem

In a three-page paper titled Is Justified True Belief Knowledge? (1961), Edmund L. Gettier claimed to have struck at the very foundation of a then rather firm tradition in epistemology, a tradition which considered knowledge as justified true belief (JTB). What is interesting about this paper is that its method is “thought experimental” – if such an adjective may be used.

Since its publication, many have acknowledge the fair death of JTB and many have tried a rebuttal of the two thought experiments it contains (as it seems quite often to be happening with thought experiments). There are standard replies and standard replies to replies, a very good exposition of which can be found in the Wikipedia article on it. Let us first take a brief look at the article.

“Is justified true belief knowledge?”

Gettier first identifies an established account which defines knowledge by reference to three sufficient conditions:

S knows p iff (a) p is true, (b) S believes that p, (c) S is justified in believing that p

The two philosophers pointed towards are R. Chisolom & A. J. Ayer. To this move some have responded as follows:

According to the inherited lore of the epistemological tribe, the JTB [justified true belief] account enjoyed the states of epistemological orthodoxy until 1963, when it was shattered by Edmund Gettier... Of course there is an interesting historical irony here: it isn't easy to find many really explicit statements of a JTB analysis of knowledge prior to Gettier. It is almost as if a distinguished critic created a tradition in the very act of destroying it. (Plantinga, 1992)

This, however, is a problem epistemologists and maybe historians of philosophy must deal with. As far as the thought experiments are concerned, even if one philosopher advanced a theory of the sort – and the theory itself is not total bogus – then an inquiry into the debate itself is not a useless assignment.

Before the definition of “S knows p if (a) (b) and (c) hold”, Gettier introduces two priciples which will be used in the thought experiment.

(i) It is possible for S to be justified in believing a proposition p “that is in fact false”

(ii) If S is justified in believing p and p "→" q, then S is justified in believing q if S is the one making the deduction and if S is making the deduction from p.

Again, one might feel the need to claim that these principles are not immediately acceptable within the debate. I think a similar criticism applies to both. First, the subtle insertion of “in fact” in (i) is problematic. If p is “in fact” false, then S is “in fact” not justified in believing p – but only “apparently” or “as far as he knows”. It’s hard to tell whether this affects the thought experiments and their conclusion, but nevertheless a preliminary question could have been addressed: Does S know p if p is true (according to him) but false (according to us)?. Second, the possible ambiguity of “justified” appears in (ii): S might think he is justified in believing p and be really justified in believing in q. Again, I don’t know if these points affect the thought experiment, but I don’t think they’re completely irrelevant either.

John & Smith & coins & jobs

Suppose that Smith and Jones have applied for a certain job. And suppose that Smith has strong evidence for the following conjunctive proposition:

(d) Jones is the man who will get the job, and Jones has ten coins in his pocket.

Smith's evidence for (d) might be that the president of the company assured him that Jones would in the end be selected, and that he, Smith, had counted the coins in Jones's pocket ten minutes ago.

Proposition (d) entails:

(e) The man who will get the job has ten coins in his pocket.

Let us suppose that Smith sees the entailment from (d) to (e), and accepts (e) on the grounds of (d), for which he has strong evidence. In this case, Smith is clearly justified in believing that (e) is true. But imagine, further, that unknown to Smith, he himself, not Jones, will get the job. And, also, unknown to Smith, he himself has ten coins in his pocket. Proposition (e) is then true, though proposition (d), from which Smith inferred (e), is false. In our example, then, all of the following are true: (i) (e) is true, (ii) Smith believes that (e) is true, and (iii) Smith is justified in believing that (e) is true. But it is equally clear that Smith does not know that (e) is true; for (e) is true in virtue of the number of coins in Smith's pocket, while Smith does not know how many coins are in Smith's pocket, and bases his belief in (e) on a count of the coins in Jones's pocket, whom he falsely believes to be the man who will get the job.

(Before we move to the second one, let us notice the similarity between this thought experiment and a classic scenario depicted by K. Donnellan in his paper on Reference and definite descriptions (1966). In that paper, Donnellan was arguing against the classic positions on reference assumed up to that point by Russel and Strawson by conjecturing a distinction between two uses of definite descriptions, a referential and an attributive one:

To illustrate this distinction, in the case of a single sentence,consider the sentence, "Smith's murderer is insane." Suppose first that we come upon poor Smith foully murdered. From the brutal manner of the killing and the fact that Smith was the most lovable person in the world, we might exclaim, "Smith's murderer is insane." I will assume, to make it a simpler case, that in a quite ordinary sense we do not know who murdered Smith (though this is not in the end essential to the case). This, I shall say, is an attributive use of the definite description.

The contrast with such a use of the sentence is one of those situations in which we expect and intend our audience to realize whom we have in mind when we speak of Smith's murderer and, most importantly, to know that it is this person about whom we are going to say something. For example, suppose that Jones has been charged with Smith's murder and has been placed on trial. Imagine that there is a discussion of Jones's odd behavior at his trial. We might sum up our impression of his behavior by saying, "Smith's murderer is insane." If someone asks to whom we are referring, by using this description, the answer here is "Jones." This, I shall say, is a referential use of the definite description (Donnellan, 1966, pp. 285-286)

This distinction, as well as the two scenarios, were afterwards (again) fiercely discussed by Kripke, Searle and Bach. I have posted a few times on this problem and its tradition, see here.)

John & Smith & Brown & cars

Let us suppose that Smith has strong evidence for the following proposition:

(f) Jones owns a Ford.

Smith's evidence might be that Jones has at all times in the past within Smith's memory owned a car, and always a Ford, and that Jones has just offered Smith a ride while driving a Ford. Let us imagine, now, that Smith has another friend, Brown, of whose whereabouts he is totally ignorant. Smith selects three place-names quite at random, and constructs the following three propositions:

(g) Either Jones owns a Ford, or Brown is in Boston;

(h) Either Jones owns a Ford, or Brown is in Barcelona;

(i) Either Jones owns a Ford, or Brown is in Brest-Litovsk.

Each of these propositions is entailed by (f). Imagine that Smith realizes the entailment of each of these propositions he has constructed by (f), and proceeds to accept (g), (h), and (i) on the basis of (f). Smith has correctly inferred (g), (h), and (i) from a proposition for which he has strong evidence. Smith is therefore completely justified in believing each of these three propositions. Smith, of course, has no idea where Brown is.

But imagine now that two further conditions hold. First, Jones does not own a Ford, but is at present driving a rented car. And secondly, by the sheerest coincidence, and entirely unknown to Smith, the place mentioned in proposition (h) happens really to be the place where Brown is. If these two conditions hold then Smith does not know that (h) is true, even though (i) (h) is true, (ii) Smith does believe that (h) is true, and (iii) Smith is justified in believing that (h) is true

This one is a bit simpler since it does not involve any definite descriptions. However, the objections to (ii) do apply: it is not clear in what sense S is justified in believing (h) if Jones does not own a Ford. Some early responses attempted to save JTB by rejecting (ii) – thus, by adding the condition that the belief not be inferred from false premises. An example of this is given by Wikipedia:

After arranging to meet with Mark for help with homework, Luke arrives at the appointed time and place. Walking into Mark's office Luke clearly sees Mark at his desk; Luke immediately forms the belief 'Mark is in the room. He can help me with my logic homework'. Luke is justified in his belief; he clearly sees Mark at his desk. In fact, it's not Mark that Luke saw; it was a marvelous hologram, perfect in every respect, giving the appearance of Mark diligently grading papers at his desk. Nevertheless, Mark is in the room; he is crouched under his desk reading Frege. Luke's belief that Mark is in the room is true (he is in the room, under his desk) and justified (Mark's hologram is giving the appearance of Mark hard at work).

A further objection might be advanced, this time as to what Gettier means by having justification for something. One might interpret the phrase as "there being something out there that can justify one's belief". One might choose to say Jones has justification for believing that man landed on the moon when Jones believes that unjustifiably, i.e. without considering the justificatory evidence. But one might also interpret it as "there being something out there that can justify one's belief and that person using it as such". In this case, we could not say the same about the situation with Jones' belief of man landing on the moon; there is a justification out there, but Jones does not have it.

Gettier did not propose any solution to this problem, which is how he managed to keep his paper so short.

PS: In order for the discussion not to be jumbled one might formulate the following question: How can two discussants agree on a standpoint but disagree on the arguments which must be taken as a good defence of that standpoint? At first glance, it is simple: they just don’t agree on the arguments but they (happen to) agree on the conclusion. But is this even possible? They might also disagree on the standpoint “P because Q”, or something similar.

Alvin Plantinga (1992). Warrant: The Current Debate. Oxford University Press. pp. 6–7

The world & everything

2012-01-20T21:03:00.001+02:00

Leibniz’s Monadology (1714) is anything but a cosy, Sunday-afternoon read. We know Bertrand Russell was an avid reader of Leibniz’s work and its exegesis. Russell even wrote a book on it, A Critical Exposition of the Philosophy of Leibniz (1900). We know that. We know that and we cannot understand why. Leibniz's writing is callous and it is frustrating.

Nevertheless, here and there we find a piece of argumentation. And argumentation in those days was a hot bowl full of spaghetti with more geometrico, thank you. For instance, in order to prove that the world is made out of teeny-tiny souls – “monads” – which receive unique and infinite understanding from God, he went as follows.

First, two postulates:

I. Every substance is either simple or compound.
II. A compound substance is composed of simple substances.

Nice. But let one not be fooled by simplicity. These be starting points treacherous and deluding! Anyway, a conclusion certainly follows.

III. Every substance is either simple or composed of simple substances.

We then lay down two additional postulates:

IV. Each material substance has a divisible extension.

Has a what? An extension of a substance is, in Descartes’ terminology, is the amount of space matter occupies. Let it be said that, by borrowing this scholastic concept, Descartes was perfectly mudded in an old medieval metaphysics as to the distinction between mind and matter (intension and extension). But be it. The next postulate is:

V. Nothing that has a divisible extension is a simple substance.

Exactly, right? Because it is a divisible extension. But take III, IV & V, and state it clearly so that Russell can hear you:

VI. No simple substance is a material substance.

And, if not material, we know what’s left:

VII. Every substance is either material or spiritual

Hence,

VIII. Each simple substance is spiritual.

Good night!
PS: For those sufficiently sadistisch, check the Monadology for why every monad is a perceiving being!

A dilemma for thought experimenters

2012-01-17T18:02:00.000+02:00

Thought experiments do not have a life of their own ... because of the following dilemma. We either have experience with a situation that is relevant to the thought experimental situation or we don’t. If we do, then our thought experiment just tells us what we know from concrete experiments (or observations). But if [we] don’t, then the thought experimental result amounts to mere guesswork.

Sure, but it depends on what you mean by "guesswork". In a sense, if it means "not being based on direct or reported experience", then yes. Now, many other forms of whatever you might think of as evidence (arguments, for instance) will be guesswork just as much. If, however, "guesswork" means "random conclusions that draw upon intuition" then sure again, but then we're agreeing to a rather different conclusion, for the suggestion is that the outcome is irrational. One way out of this dilemma was famously supported by Norton (1996), who recognizes the split in the road but saw a way out.

Norton, J. (1996). Are thought experiments just what you always thought? Canadian Journal of Philosophy, 26(3), 333–366.

Reiss, J. (2002). Causal inference in the abstract or seven myths about thought experiments. Technical Report CTR 03/02, Centre for Philosophy of Natural and Social Science, London School of Economics, London, UK

The transactional/interactional distinction

2012-01-16T01:08:00.001+02:00

This distinction is often made in connection with two purposes (or functions) of language use. To use language is to attempt to achieve both at some level, with more or less interpretation needed to discern or explain these functions. Similar distinctions such as representative/expressive (Buhler), referential/emotive (Jakobson), and ideational/interpersonal (Halliday) follow a similar path.

The first one then is the transactional function: we (i.e. humans) use language to send messages with content, to send, that is, a representation of a non-linguistic content into a linguistic form. In the history of linguistics nobody was narrow-minded enough to claim that this is the only function of language, but often analysts have abstracted away from other functions in order to study what is “delivered” from one party to the other. The term “propositional content” is often used by semanticists who wish to state in very precise terms what a proposition communicates, regardless, as it were, from where and why and by whom it is uttered. It is assumed, as it where, that what the speaker primarily has in mind is a transfer of information.

The second function is the interactional function: we (i.e. humans) use language to establish and maintain various sorts of social relationships. Sociologists and anthropologists often speak of the phatic function of language and are keen to point that some of our everyday talk can even be said to have this function above the first one. As Brown & Yule (1983) notice that

“when two strangers are standing shivering at a bus stop in an icy wind and one turns to the other and says ‘My goodness, it’s cold’ it is difficult to suppose that the primary intention of the speaker is to convey information. It seems much more reasonable to suggest that the speaker is indicating a readiness to be friendly.”

Context & discourse analysis, love & marriage

2012-01-15T04:24:00.001+02:00

To say that context influences communication is close to saying that the sport you are practicing influences what you might do during training, at competitions, what you must do for a medal and so on. Naturally however, while the influence of the context is recognized, theorists are not at all ready to jump in the same bucket of consensus when it comes to answering how this influence manifests itself and is to be studied.

To begin with, the question what is context? is itself quite spiny. I believe most natural language users would understand the notion in opposition to the text (it is the thing in which the text comes, which is different from the text in that it is somehow in the background). In a more technical language, the focal event - the actual text, if there is such a thing - is differentiated from the context. As a first, negative definition, it works just fine. Now, assuming there are instances of actual texts which somehow “do not need” the context – where does this context-thing first appear on a gradual scale of, let’s say, context-independence to high-context-dependence?

Most pragmaticians would start with deixis. That, at least, is something of a consensus. When I say “I said I will” I say something quite different than when you say “I said I will”. [Often, other factors such as tu/vous distinction (je/u in Dutch) have been called “social deixis”]. But what next? You can feel the ground getting shaky. One of Sacks’ mini-stories (The baby cried. The mommy picked it up) is dauntingly simple if it proves that huge chunks of socio-cultural contexts come into play at every step – for instance, the idea that mothers usually take care of their babies, that picking a baby up can be a response to a cry. Because, you might not have noticed, but it in the picked it up could very well refer to a bowl of soup: so how come it [sic!]… does not?

And it gets even worse in two ways. Context is not only highly resistant to theory-formation. It is also, first, something actors “negotiate” during speech. The focal event is built (see Gumperz’s contextualization processes) partly as presupposing but partly as generating the context. In at least one sense we can be sure of this statement: new text creates, in its bare minimum, new co-text for what preceded and what follows. Only, of course, considerations should land on the more abstract (social, institutional, culture) levels of text-context interaction.

Second, a distinction between several contexts for seems at once highly de-stabilizing and highly needed. When two parties are speaking and only those two studied, great. But there are social events with audiences and where the speaker and the communicator differ, and situation where the hearer and the receiver of the message differ, and finally situations where the audience and the over-hearers differ. In other words, it is not only a matter of systematizing (or ‘formalizing’) contexts and making their relationship with texts apparent, but also, in a way, ‘assigning’ them the party one wishes to study. Can anything be more difficult?

The (real) purpose of language…

2012-01-12T14:50:00.001+02:00

A common explanatory attempt has been to point out the relationship between brain size and group size: the larger the groups in which animals live, the more there is a need for organization, the maintenance of complex and/or multiple social relationships, and often a division of labour, too. To interpret all the relevant information, more brain power is needed, which, in turn. stimulates the development of more complex communication systems. This process of the mutual reinforcement of strictly distinct properties within the same species might be seen as a form of 'co-evolution'. In conjunction with such observations the argument is often made that language developed primarily for bonding purposes, as an extension of primate grooming behaviour. Evidence for this is sought in the prevalence of social talk in ordinary conversation. (Verschueren & Brisard, 2009)

Thus,

Pragmatics as domain and pragmatics as perspective

2012-01-10T17:48:00.001+02:00

Pragmatics does not study language as a system of signs, but as a tool. In French, we would say pragmatics deals with le langage not with la langue. Sometimes, this is explained by saying that pragmatic theories seek to explain user-choices. Everyone makes choices while using a language: one pronounces differently, orders words differently, means things differently, interprets things differently etc. The job of pragmatics is to explain these choices – not the reasons behind them, be it psychological, social etc., but the purpose with which they are made. (Notice, here, the relationship with the philosophy of pragmatism which was, broadly speaking, interested in the way processes, meaning-generating processes in particular, were connected to their purpose. The term, going even further back in time, is connected with Kant’s pragmatisch).

The cradle of pragmatic inquiry, whether in hindsight worthy of the current meaning associated with the term “pragmatics” or not, is usually situated in the almost Cartesian project of Morris (1938). Morris’ aim was to come up with a unified theory of signs (semiotics) which would bring together logicians, linguists, philosophers, psychologists, anthropologists, sociologists and others. Morris identified the three actors involved in semiosis and called them “sign (vehicle)”, “designatum” & “interpreter” (the labels are fairly intuitive). Semiosis is then a triadic relation, a correlation of the sign, the designatum and the interpreter which we might call, today, communication. Aside from this observation, six dyadic relations can be abstracted for further inquiry: sign-interpreter, designatum-vehicle etc. Pragmatics is then the relationship between signs and interpreters.

This definition has to be placed in the intellectual context of the emergence of semiotics as a philosophical reflection on the 'meaning' of symbols. often triggered by the use of symbols in science and hence related to developments in the philosophy or theory of science but soon expanded to all other domains of activity involving what Cassirer calls 'symbolical animals', i.e humans. (Verschueren, 2009, p. 3)

Inevitably, pragmatics came out eventually as a tremendously complicated and interdisciplinary endeavour, its roots being connected certain developments in psychology (Mead, Malinowski etc.), philosophy of language (Wittgenstein, Austin, Searle) and social theory (Hambermas). An “anthropological trend” also became visible early on, and here the works of Gumperz & Hymes (1972) Direction in sociolinguistics, Hymes’ (1974) Foundation of sociolinguistics, and Gumperz (1982) Discourse strategies stand as building-bloks. The anthropological approach was driven by the attempt to study discourse in context, without abstracting away from the social, cultural & “institutional” aspects of communication. It is why this approach is sometimes labelled as ethnographical, thus covering the field of conversation analysis (Garfinkel, Sacks, Schegloff etc.) The intuitive notion of context became more and more theory-laden.

The history of these developments can also receive an organization into schools, although many developments would be left aside if this approach were undertaken. The French school of linguistics (Ducrot, Anscombre etc.), the Prague school (Mathesius, Firbas etc.) are some of the more stable approaches.

A more common perspective is that of topics. It is sometimes acknowledged that pragmatics delineated its field as a result of developments in other fields. Some topics, as it were, ended up as constituting the subject-matter of a pragmatic endeavour and this is often referred to as “the wastebasket view of pragmatics”. For instance, the Chomskian distinction between competence & performance, for instance, simply leaves all subject connected to performance “outside grammar & semantics” – thus creating a new subfield as a by-product. (The twofold form vs. use distinction is today very much left as a stepping stone worthy of no more than historical interest). In the wastebasket of pragmatics we find highly interesting yet fairly disconnected subjects or topics (deixis, implicature, presupposition, conversation etc.). Although attempts have been made to unify this set of distinct approaches to distinct issues – Sperber & Wilson’s Relevance theory, Levinson’s (2000) Presumptive meanings – no theory has managed to gain consensus. Morris’ ideal of a unified theory of signs seems more and more an impossible undertaking.

Topical and methodological unity are required criteria if we are to speak of the field of pragmatics, complementary to other fields within the broad domain of linguistics. If there is methodology in logic and grammar – why shouldn’t it be in pragmatics?

Gazdar’s (1979) textbook famously introduced the idea of pragmatics as “meaning minus truth conditions” (alluding to Kempson’s (1975) theory of semantics as the study of truth-conditions) is but one path. The what-is-conventional vs. what-is-non-conventional approach (more or less accepted by Levinson’s (1983) textbook) is another one. Reference to context – i.e. defining pragmatics as the study of meaning in context – is yet another one. Verschueren (2009) observes in these approaches, with some degree of generality, a certain “fear of trespassing into the realm of sociolinguistics and psycholinguistics” (p. 12).

It should be clearly noted that multi- or inter-disciplinarily has not always been seen as an imperfection. Some textbooks even underline the benefits of such a state within a field of inquiry - for instance, one benefit would be the rise of well-structured theories on specific topics (Sperber & Wilson’s 1986 Relevance theory being one example). And, as some have pointed out, so long as agreement on what constitutes proof in pragmatics is not achieved, a grand project might even be to incoherent to be safe. It is then often asked: What counts as empirical evidence in pragmatics?

One way out of this is to refuse the view of pragmatics as a domain (with specific principles of rational and empirical justification) but as a perspective. A perspective on what? On whatever linguists (phonologists, semanticists, etc.) deal with. Some subjects from these fields will lend themselves to being studied from the perspective of pragmatics, some will not. This demarcation does not spoil the unity of the fields/domains/subject-matters in question. Verschueren (2009, p. 16) supports this tactic as follows:

There is at least one essential difference between pragmatics and what we have referred to as components of linguistics. In contrast with phonology with phonemes as basic units of analysis, morphology with morphemes, syntax with sentences, and semantics with propositions or lexical items, pragmatics cannot - without undue oversimplification – be said to have any basic unit of analysis at all […]

Methodological pluralism will arise from the plurality of objects under study and various types of evidence will receive acceptance if the object allows and if an advance of relevant knowledge can be extracted.

As a perspective and a functional one, pragmatics asks What is it to language use? by asking What does using language do for human beings and what do human beings do with language? It is thus part of action theory, where modes of action (one specific mode where others could have very well taken its place) are described and explained.

Wrong? No. Right? No. What else?

2012-01-09T21:30:00.001+02:00

The first arguers out there were, after every definition, quite obtuse. I am thinking of the Milesian School. And it is not as if they were wrong in their approach, ignorantly wandering them fields unbeknownst. In fact, if we judge their capacity of getting along with what they had, they were quite sharp. So what makes them stupid?

Well, they were what we today might call physicists. They were not interested in the why’s and the what now’s but the what-of’s and what-from’s. That, at least, is the image we get from Aristotle’s depiction of their interests – the only one unfortunately. And it is as physicists that they appear to us as rather narrow minded. Otherwise, it is hard to see something wrong with the argument that the world was made in the same way tempests and lightning is born in the middle of the sea: the wind, Anaximenes tells us, is sometimes captured inside clouds; it then fights and struggles until it manages to crack one of them open, producing that violent, formidable clatter called thunder. Rather poetic but, as we now know, this is what happens.

And everything went like this. Men at the brink of a continent, pushed away by the Persian empire more and more into the sea, for them more or less everything must happen in the way natural phenomena happens at sea. The formation of the Earth, that of the stars, neither should be much different. Doesn’t water evaporate, producing clouds which produce rivers which brings alluvia, with all its life and support. Doesn’t it follow, then, that everything is made, literally, “out of” water?

We might appreciate this lack of “oh, Ol’ Daddy and Ol’ Mummy did every blessed thing around here!”. But if we do we should also be ready to evaluate these arguments. How in the world could one do that? What are the evaluation criteria for arguments which are blatantly false, in an epoch where they were strikingly obvious? And even assuming we find such criteria (with a little help from historians and great commentators of ancient text) what will the decision look like? If it is a confident “a-ha!” in the face of empirical error, then the analyst should settle for nothing more than being the uninteresting executioner of false beliefs. If it is a detailed and qualified “welly-well, here’s how you should view it”, then the analyst should be prepared to counter the accusation of relativism.

Now, the Milesian School aside, in The Poverty of Historicism, Karl Popper meticulously puts forward a bunch of arguments for why neither of the two is the right thing to do with respect to historical judgements of this sort. Well, maybe not of this sort precisely, but with ones having to do with social phenomena, judgements which, one should assume, are just as bad in the past as they are now. But if the right thing is somewhere in-between: Who decides where this right spot is?

When you write like this

2012-01-04T13:34:00.001+02:00

Among the easily discernible differences between medieval and post-mediaeval philosophy there is a striking difference in forms of literary expression. For one thing, whereas the mediaeval wrote in Latin, in the post-mediaeval period we find an increasing use of the vernacular. It would not, indeed, be true to say that no use was made of Latin in the pre-Kantian modem period. Both Francis Bacon and Descartes wrote in Latin as well as in the vernacular. So too did Hobbes. And Spinoza composed his works in Latin. But Locke wrote in English, and in the eighteenth century we find a common use of the vernacular. Hume wrote in English, Voltaire and Rousseau in French, Kant in German. For another thing, whereas the mediaeval were much given to the practice of writing commentaries on certain standard works, the post-mediaeval philosophers, whether they wrote in Latin or in the vernacular, composed original treatises in which the commentary-form was abandoned. I do not mean to imply that the mediaeval wrote only commentaries; for this would be quite untrue. At the same time commentaries on the Sentences of Peter Lombard and on the works of Aristotle and others were characteristic features of mediaeval philosophical composition, whereas when we think of the writings of seventeenth-century philosophers we think of free treatises, not of commentaries.

(Copelston, 1994, p. 5)

People with a propensity for literary criticism & cognitive sciences, if they’re out there, should wonder how the predominant genre of an epoch affects the predominant beliefs. Hard to isolate, maybe, but one cannot help thinking that when you decide to write in commentaries you decide more than just the spacing and the subject of your sentences. Amongst other, maybe more subtle, things you also choose the amount of personal input you are expected to produce.

The equivalent nowadays? Is there an equivalent nowadays? Are the scholarly genres of the twenty-first century rigid and obstructive? Maybe not. At least not apparently. But think of the academic paper. Who decides what counts as and what cannot count as a scholarly paper? And on what grounds does one make this decision? Isn’t novelty amongst the criteria? Could you possibly get through with a paper that brings up nothing novel? So then, aren’t you forced – the word might be harsh, but you are, in a sense, forced by the context – to bring about something new if you want to get published? This might be so. And not only in the natural (hard) sciences, where even if you are engaged in testing an old hypothesis, you are doing so after a new fashion (with new data, by a new method etc.) It is also the case, maybe even more so, in social sciences and, ultimately, in philosophy. Post hoc ergo propter hoc? Possibly, but here’s a nice research idea for an argumentation theorist: How authors manage to convey the message that their paper is new, i.e. brings something novel, to the field in which it is produced. Strategic manoeuvring, straight-out argument structures, linguistic devices, implicitness – the whole deal.

Aye, aye, capitan! Ad Verecundiam it is

2012-01-02T15:56:00.001+02:00

There is, I think, a muted historical side-note to every discussion on ad verecundiam. As neat historians will tell you, philosophy and science have risen precisely against blind faith in authority. To take a conveniant example of both in one,Thales didn’t say everything is made out of water simpliciter or that everything is made out of water because Zugma-Bugma said so. As was the Milesian School’s wont, they argued – poorly, but cunningly – for what they claimed. “Water is best!” was Thales’ one-liner, but it did not end there. Russell adds, not without a touch of irony: “The statement that everything is made of water is to be regarded as a scientific hypothesis, and by no means a foolish one. Twenty years ago, the received view was that everything is made of hydrogen, which is two thirds of water.” (Russell, 1946, p. 44). And that to say nothing about the geometrical, utterly non-religious proofs attributed to Mr. Thales. Ta-naa!

But in a way argumentation theory also had its incubation in the revolt against authority – although an authority of a less religious stripe. The problem of authority in arguments is thus pressing: if, in arguing, we sometimes appeal to experts, and if, in appealing to experts, we are not invariably committing a fallacy, where do we draw the line? Despite its immediate applications (“tell me where the line is and I’ll tell them if their appeal to authority is fallacious or not”), this is a very philosophical issue. I say “philosophical” because of this question underlying the abovementioned one: What makes an argument fallacious?
Really? Are we still floundering around this question? I think so. Pointless? Maybe. Instructive? Sure. Engageons-nous!

The problem of part-time fallacies is that you have to identify a class (The X’s) and a subset within this class (The “Bad” X’s) without saying to much about the specific socio-cultural circumstances pertaining to the evil subset. To do otherwise would be fishy: if we judge the fallaciousness of arguments by their “field”, then relativism and ultimate futility are not very far. I keep putting “argument” in italics because of the solution found by Walton (1995; 1997; 2006a). As his pragmatic theory of fallacy led him, Walton found a cute way out of the dilemma of appeal authority. First, he makes distinction in the meaning of “Bad” from “The ‘Bad’ X’s”: there are weak-Bad and fallacious-Bad.

Many of these cases are not fallacious ad verecundiam arguments, but are weak arguments based on appeal to expert opinion. (2006, p. 754)

Unfortunately, the distinction is only gradual and he continues with showing how some weak arguments are “not so bad that [they] should be called fallacious” (754). But anyway, blurred as it may be, the category of “fallacious-Bad” appeals to authority is there. Thus, assuming there are some clear-cut cases which exhibit the essential properties of an appeal to authority which is fallacious-bad, what would such a case look like?

The fallacious cases seem to be the ones where the arguer who appeals to expert opinion tries to preclude or shut down the examination interval. The fallacious cases, according to Walton (1997), are ones where the arguer tries to block off or shut down the possibility of critical questioning of the appeal to expert opinion through the use of certain argumentation tactics. Often these tactics are of a pre-emptive sort, showing that the proponent of the appeal to expert opinion is not really open to critical questioning at all, even though she may give a surface appearance of being so.

This, however, is not a solution to the problem we were formulating. Remember the italics? We are interested in the fallaciousness of the argument from expert opinion, not in the fallaciousness of the moves with which the arguer tries to preclude or shut down the examination interval. If the analyst identifies some speech acts that might fit the description, a “blocking move” as it is termed in (Walton, 1997), then those speech acts, not the ones constituting the argument, are fallacious. If the authority is invoked as the last word on the subject, then it is the linguistic means of conveying this that are fallacious, not the argument itself.

Thus, if not by blocking a legitimate shift to an examination dialogue, when are appeals to authority fallacious?
There are certainly many things that can go wrong with the authority. The classic procedure is to identify a scheme, a couple of critical questions and a set of criteria for judging when those critical questions are observed. The student is advised to do this: take the raw text, identify the scheme, formulate the critical questions, see whether there are well dealt with, judge.

But notice, again, the more philosophical question underlying this advice: The only way an argument can be fallacious is by not having its critical questions well observed. Thus, a fallacious argument is a very very very bad argument. This seems also to be the position of the pragma-dialectical approach (Eeemeren & Grootendorst, 1992; Wagemans, 2011). Only a couple of the rules of the critical discussion apply to the argumentation stage, and those rules tell us about the argument scheme and whether the critical questions pertaining to it are well-answered. In his Appeal to expert opinion (1997), Walton himself is at pains to give the most accurate description of the scheme and a well organized taxonomy of all the critical questions that might relate to that scheme (with sub-questions and everything).

The expert might be irrelevant, he might be biased, wrongly quoted etc. This, however, does not guard us against “The fallacy of appealing to the opinions of the doctor who secretly wants your grandmother dead because she is maddly in love with your grandfather”.

Assuming, however, this sort of atomism is not around the corner, one cannot help asking … is this it? “A fallacious argument is a very-very bad one”? If not, how else can an argument be fallacious, i.e. against the rules?

Aristotle, you sarky …

2011-11-07T23:05:00.001+02:00

Dutch at last

2011-11-02T15:15:00.000+02:00

Le langage selon Fry

2011-10-27T21:30:00.001+03:00

Daniel Dennett on … ah, you know on what

2011-10-24T00:36:00.001+03:00

Suppositions as not-quite-what-Fisher-says-but-ultimately-yes-pretty-much-just-that

2011-10-23T01:46:00.003+03:00

Fisher, A. (2004). The logic of the real arguments. Cambridge: Cambridge University Press

Fisher’s The logic of the real arguments (first published in 1988) is an old-school, clear-cut, plain-spoken informal logic textbook. It shows us how to identify the conclusion, how to identify reasons, it tells us that an argument is a piece of reasoning, and that in order for us to accept it, it must contain a valid inference from true premises. You know – the whole deal.

But the book does contain a chapter which, the author claims, is not very often found in other “do-it-yourself” textbooks of logical analysis (with the exception of Thomas’s Practical Reasoning in Natural Language, we are duly informed). It is about ‘for the argument’s sake…” type of arguments. This, as you will have read between the lines, must have something to do with thought experiments. Fisher does not use the label, but analyses, voila!, Galileo’s experiment on falling objects. Which, by the way, is shown to be unwarranted so stick around.

First of all, let me spill out my prejudiced, not yet fully articulated, ideas about supposition. I am very much in line with Fisher account, and it would be cheating if I would use what he says to legitimize what I think. So, for “separational” purposes, here it is. Fisher acknowledges – out of intuition, I suppose, for nobody gets quoted – that a supposition is not an assertion, it is not presented as true. When I say “Suppose we can fly”, I’m (obviously, intuitively, etc.) not committed to the fact that we could fly.

[Just a short juicy digression: “Suppose we could fly” is a philosophically perverse move. If A says this in a conversation with B, then B is not asked to accept the possibility of a world where we do fly but the possibility of a world where we can fly. In other words, we might still not be able to fly in the “Suppose-we-could-fly” world. In the “Suppose-we-could-fly” world we don’t fly, we can fly. Which is dreadfully strange: why should one suppose a world where we can fly but we don’t?]

AAAanyway. Insofar as we both intuitively sense that supposition is not assertion, we agree. Fisher writes:

If someone begins an argument by saying “Suppose that oxygen does not burn” he is not asserting that oxygen does not burn – he is not presenting it as true.

A mathematician who… is not asserting (telling us) that … but asking us to consider the proposition with a view to drawing out its implications (113, my italicys)

The section in italics is what I want to pursue, and what Fisher leaves aside (and ultimately, in the analysis of Galileo, overlooks). Suppositions are not a different kind of assertion – they are not assertions in which the commitment of the speaker is weaker or absent. I say that from a speech act theoretical perspective and by this I mean: a supposition, insofar as it does not commit the speaker to the truth of the proposition, i.e. it cannot count as an undertaking of that commitment.

Lovely. But what are they? I believe they are directives. As described by Searle (1979, p. 13) directives have a different illocutionary point from that of assertive.

The illocutionary point of these consists in the fact that they are attempts (of varying degrees, and hence, more precisely, they are determinates of the determinable which includes attempting) by the speaker to get the hearer to do something.

And look at the syntax! “Suppose …”, “Let’s assume that…”, “Imagine that…” – are attempts of varying degrees to get the hearer to suppose, to consider etc., briefly, to commit to X “for the sake of the argument”. A command requests a specific act “mop the floor”. A supposition asks for a specific act too “take this as true”. A command has a preferred response “yes, sir”. A supposition has a preferred response “ok, I will”. The felicity conditions of a command can be under doubt, so attempts can be made to justify that they hold: “Because I want you to do it”, “Because I want you to do it and I’m your boss” etc. The felicity conditions of a supposition can be under doubt, so attempts can be made to justify that they hold: “For the sake of the argument”, “Because you have hold this view before”, “Because it derives from your theory”. The speech act which I believe is closest to supposition is proposal; hence, the fitting of the “let’s” idiom. Notice that preparatory conditions hold just the same: it cannot be obvious that B will undertake the commitment to A or that he already did. The following dialogue should seem odd:

B: I think that p!

A: Well, let’s assume p!

The reason it does not sound odd is because it jumps over a few steps which are implicitly taken. So,

B: I think the Sun rotates around the Earth
A: Well, suppose the Sun rotates around the Earth.

If a supposition is a request, the above dialogue should be pragmatically odd. I hope making it a bit more explicit will reveal the oddity:

B: I think the Sun rotates around the Earth
A: Well, (let’s) suppose the Sun does rotate around the Earth.

Who’s us in the let’s? Cannot be B. B is already supposing, i.e. B is already committed to p. But if there is no “let’s”, to whom is the request directed? Notice how well “well” fits in there. And well marks the drawing of conclusions (replace it at will with “well then”, “aha! if this is the case”, “then” etc.) I think the only way we can make sense of it, is if we make it into something like:

A: I don’t think p. (Don’t think non-p either, so far). But you do. Since this is the case, I am ready to accept it myself, and critically examine it. (Wait, why am I talking like Socrates?!). So let me – and therefore, since you are already in the reduction ship – let us undertake the commitment to p.

What I am doing, in saying suppose p – if I want to critically test it in a discussion, at least, but I cannot imagine a situation where a speaker supposes p for some other reason, can you? – I say, <AGREED! I COMMIT ALSO for the sake of the argument>. Remember the preferred response to a request? Acceptance, yes. Now fly away from this subject. Imagine two robbers standing behind a fence debating whether to rob a house or not. They squabble back and forth for a while and at the end the more audacious of them convinces the other one to do it. The last one will say:

B: Ok, let’s do it.

Consider one last example: academic writing is full of let’s and let us. (John Searle, accidentally, is an avid user). I’m not saying let in “let’s” should be interpreted literally – that, because of its idiomatic character. The imperative function arises quite independently of the meaning of “let’s”. Notice that, just as with other indirect acts, some are more built in language then others. Consider how oddly polite would “allow us” and “permit us” would be. Thus, aside from its teacher-in-the-class-sounding connotations, let’s cannot be explained unless this role-play (in which the author allows himself something as if he is a different person) is understood. “Thus, let us suppose” is a note-to-self. If A wants to tackle B’s claim and says “OK, let’s suppose p” it is A (not B) who need to commit to p. And it is worth mentioning that A thereafter commits to that because in the discussion he is in fact precisely on the other side, notice the nice fit of:

“I don’t agree, but OK, I will assume p just as you assert it”

Notice, then, the differences and the similarities between some of the ideas presented here and Fisher’s account. I too think that “Speaker does not undertake p” it is a good description of what happens but the way in which this is achieved in context is more roundabout than Fisher observes. I believe supposition cannot be explained outside a difference of opinion – since “I agree, but OK, I will assume p” is odd.

So now, the parties have agreed on the setting, and the antagonist goes:

A therefore B therefore … therefore X

The protagonist can, of course, object. Aristotle, as we shall see, might have objected to some of the intermediate claims extracted from his theory of motion. (Notice, parenthetically, that this time, although roles are played, the speaker is asserting A, otherwise he cannot make an argument. Fisher overlooks this, as I said earlier).

But if he, the protagonist, doesn’t object, then the antagonist has henceforth established – for the purposes of the discussion – the claim:

If A, then X

If what we’re playing here is theory choice, then A is a (or part of a) theory. It is a theoretical commitment.

After this, as the German would say, tout ira de soi.

If A, then X
But X is not the case.
Therefore A cannot be the case.

Old, overcooked modus tollens. Of course, at this point, we should like to say that the protagonist had better object. But, as it happens, the protagonist is seldom there to slap the antagonist (dialectically, I mean, of ocourse) in the face. So, once arrived at the conditional, it is hard to go back, since no sensible bloke would object to non-X. (Don’t be fooled by the easy-talk. You should not agree that this is what usually happens. It is just my feeling that this is how the strategy is commonly used. If the antagonist overlooked a thing that might make X true, he will make the frontpage of the FailWeek journal. Take Einstein’s epic one in clock-in-the-box.

If UNCERTAINTY PRINCIPLE, then you CANNOT MEASURE THE SYSTEM SO THAT BLABLABLA

But you CAN MEASURE THE SYSTEM SO THAT BLABLABLA

Therefore the UNCERTAINTY PRINCILPE cannot be the case.

As it happened, you could not.)

Oh, geez, where were we? A, right, Fisher’s account of Galileo…

To be continued.

The “both … and …” view

2011-10-23T01:46:00.001+03:00

De Mey, T. (2003). The dual nature view of thought experiments. Philosophica, 72, 61-68

What De Mey tries in this article is to show that the argument view and the experiment view on thought experiments are just that, namely, views. Neither of them is true – in the sense of capturing all there is to capture about thought experiments – but neither of them is false – in the sense of being logically rejected by the others. Thought experiments are both.

According to contemporary wisdom, one either holds that thought experiments are, basically, experiments or one subscribes to the rather deflationary view that they are, deep down, arguments 62

Now, De Mey’s plan is methodologically very shipshape: let’s first ask ourselves why we are wrestling with thought experiments in the first place, and then see what is the “nature” of thought experiments. Insofar as the theoretical (or meta-theoretical) purpose is in the blur, talk of whose definition is better is blank.

There are three problems, De Mey recognizes: (1) the problem of source of knowledge, (2) the problem of heuristic value, (3) the problem of evidential significance.

First: where do the goodies come from? “The very possibility of acquiring knowledge by means of thought experiments is generally taken to be a problem for empiricists” since it makes this knowledge difficult to trace back to experience. One way out of this is Norton’s empiricist account:

Thought experiments in physics provide or purport to provide us information about the physical world. Since they are thought experiments rather thanphysicaZ experiments, this information does not come from the reporting of new empirical data. Thus there is only one non-controversial source from which this information can come: it is elicited from information we already have by an identifiable argument, although that argument might not be laid out in detail in the statement of the thought experiment. The alternative to this view is to suppose that thought experiments provide some new and even mysterious route to knowledge of the physical world.

The “mysterious route” being surely Brown’s platonic account. Some thought experiments, Brown argues, do two things: they destroy a theory and build a new one. While the first part might be reconstructible as argumentation, the second part is not. Also, the second part does not involve new knowledge, nor does it derive its claim from previous data. (This should be taken with a grain of salt, since the fact that some conjunction of hypotheses cannot be the case can already be qualified as knowledge.)

Now, in connection to the second problem (the “heuristic value”), De Mey adds: “Whatever the merits of Norton's argument view are, it does not explain why thought experiments can be "psychologically helpful" (and thereby rhetorically effective)” (65). I agree with De Mey, but I think we hold this view for different reasons. He construes Norton’s account as theoretically incapable of shedding light on the rhetorical prowess of TE’s, while I construe Norton’s account as theoretically undeveloped, with the same result. In other words, is not like the account cannot say something explicatory about the heuristic value, it is that it does not. Just one step forward: although it does not, not only that it can, but it seems to me like it is the only one that can give a satisfactory answer. And half the road is already travelled: they are rhetorically effective because they are good arguments!

As for their epistemic significance, De Mey (2003, p. 66) speaks of the role TE's play in theory choice as their most "spectacular capacity" - whereas I think one should construe it as one of their defining ones. I think we would miss the property of terms if we would speak of a thought experiment every time someone supposes something. If any supposition triggers a thought experiment, then the label loses its classificatory values, i.e. it ceases to isolate a group of entities for the purposes it used to.

Norton's empiricist solution to the problem of the source of thought experimental knowledge can give us a first hint. Nobody doubts that arguments can play a role in theory choice. So, as far as thought experiments are arguments, their evidential significance seems fairly unproblematic (66)

There’s also Bishop (1998; 1999). He claims that the clock-in-the-box event works as an illustration as to why thought experiments are not arguments. The clock-in-the-box was a failed attempt by Einstein to confront Bohr with a counterexample to the uncertainty principle. It was considered a failure because, using the same set-up, Bohr pointed out that Einstein was missing something: in order to weigh the box, it must move in a gravitational field - since it does, the uncertainty principle (the measurements in question being mass and energy) holds.

Ok, now De Mey’s view. While beginning, he uses words in a certain way and, although he slides quickly to the more urgent problem, I believe he makes a good choice which needs underlining. Notice that for him, the thought experiment is not an experiment and an argument but a description of both:

thought experiments like that of the clock-in-the-box have a dual structure: they involve (1) the description of an imaginary situation and (2) the description of its settlement or winding up.

Their “evidential significance” is different according to what points (1) and/or (2) we choose to take into account. So much so that De Mey speaks of evidential significance₁and evidential significance₂.

The last step for De Mey is to take a modern account of experimentation and cast thought experiments into it.

Sophisticated conceptions of experimentation, typically invoke more structural dimensions. Radder (1996), e. g., differentiates between three "phases" of experimentation: (1) preparation, (2) interaction and (3) detection. Firstly, during preparation the object and the apparatus are prepared in agreement with the plan of the experiment. Subsequently, interaction results in the transfer of information from the object to the apparatus. Finally, detection involves obtaining the information "by measuring or observing the relevant property of the apparatus (Radder 1996: 11).

Each phase (“make the device”, “use the device”, “read the device”) has a material realization and a theoretical interpretation. The first one is (or should be) theoretically-independent. The second one is theory-driven.

So there you have the solution:

So there are two ways to describe a thought-experimental process, i.e. in terms of its material realization and in terms of its interpretation. To do full justice to the evidential significance of a thought experiment then, of whatever kind it is, we need both. As far as the material realization of the thought-experimental process is what adherents of the experiment view on the nature of thought experiments stress (as I believe they do) and as far as the theoretical interpretation of the thought-experimental process is what adherents of the argument view have in mind (as I believe they do), we can safely conclude that it doesn't make sense to say that thought experiments are, basically, either experiments are arguments. They are, deep down, both experiments and arguments 76

Balls, electrons, cats and shrinking folks (to say nothing of amoebas)

2011-10-23T01:45:00.001+03:00

Brown, J. R. (1991). The laboratory of mind: Thought experiments in natural sciences. London/New York: Routledge.

Illustrations from the laboratory of mind. This is the title of Brown’s (1991) first chapter. In the preface, and again in the introduction to this chapter, Brown acknowledges – in an explicit manner, which I fancy – the fact that he hasn’t got a definition to work with.

Thought experiments are performed in the laboratory of the mind. Beyond that bit of metaphor it’s hard to say just what they are. We recognize them when we see them: they are visualizable; they involve mental manipulations; they are not the mere consequence of a theory-based calculation; they are often (but not always) impossible to implement as real experiments either because we lack the relevant technology or because they are simply impossible in principle. If we are ever lucky enough to come up with a sharp definition of thought experiment, it is likely to be at the end of a long investigation.

But as he advances, he adds some spice. First he brackets out what are not thought experiments, that is, psychological experiments on thought or other inky stuff. Then he explains the “experiment” component as follows:

As well as being sensory [i.e. they are visualizable or experiencable], thought experiments are like real experiments in that something often gets manipulated: the balls are joined together, the links are extended and joined under the inclined plane, the observer runs to catch up to the front of the light beam. (Brown, 1991, p. 17)

The thought experimenter does two things: imagining and manipulating.

1. Galileo on falling bodies

Galileo first notes Aristotle’s view that heavier bodies fall faster than light ones. This was the prevailing view of motion and it had the advantage of being very close to one’s intuition: if a feather falls on your toes, you’re fine. But Galileo reasoned as follows. Suppose we tie two objects together: a cannon ball and a musket ball.

First, the light ball will slow up the heavy one (acting as a kind of drag), so the speed of the combined system would be slower than the speed of the heavy ball falling alone (H > H+L).

This might sound fishy to begin with, but imagine someone hopping in a fast-moving carriage. In order for the whole system to keep the speed, the poor horses need more strength, therefore, with the same strength put into action they will be slowed down.

On the other hand, the combined system is heavier than the heavy ball alone, so it should fall faster (H+L > H).

This does not sound fishy at all. It is heavier, and it should fall faster – so intuition tells us. But, of course, this is just half of the story, because Galileo does not only expose the paradox of Aristotelian mechanics, but resolves it. The right equation, he says, is that H = L = H+L. That is, all things fall at the same speed. (Namely, some will add, gravitational speed).

2. Stevin on inclined planes

So we have three self-evident situations: if a weight is on an horizontal plane, it will remain at rest; if a weight is on a vertical plane, it will fall; and if the weight is on an inclined plane, it will either fall or rest depending on the inclination. Great, but how could we get more precise about these things? If we could calculate the point of echilibrium, that would be great: every smaller inclination of the plane means rest every greater inclination means fall.

Stevin come up with this thing:

From the first figure, we wouldn’t know what to say: are the balls in an equilibrium? From the second, however, we are compelled to say: they must be, otherwise it would be perpetual motion (and perpetual motion is an absurdity, as far as we can know). Therefore,

when we have inclined planes of equal height then equal weights will act inversely proportional to the lengths of the planes

Swell.

3. The flat planet with shrinking people

Now, Brown makes an interesting claim, which can only be understood under a very broad definition of the term “thought experiment”: “Consequently, [i.e. since Euclidean geometry is an a priori abstraction from everyday mechanics]we can see the results of Euclidean geometry (at least those produced before the rise of non-Euclidean geometry) as a vast collection of thought experiments” (p. 11). And further, “theorem of Euclidean geometry is then a kind of report of an actual construction carried out in the imagination.”

The thought experiment related to Euclidean geometry is one devised by H. Poincaré and H. Reichenbach. (The text is from Cohen, 2005, p. 45):

Imagine a planet made only of gases. At the centre the temperature is very high, and this is where all the gaseous people evolved and normally live. At the surface, however, the temperature is very, very low. In fact, M. Poincaré tells us, it is absolute zero. (The significance of this will become clear later.) As the gaseous people, let us call them ‘the Jeometers’, move around their planet, a small but subtle change takes place. Because of the change in temperature, the further they go from the centre, the smaller they become. And not just them, the smaller all the creatures and all the artefacts of the gaseous planet become. The most important thing is that everything changes at exactly the same rate, so nothing gets out of kilter.

One year, the Jeometers determine they must explore the upper reaches of their planet and construct a massive ladder which they stand upright with its top disappearing far into the clouds. One of the Jeometers’ geometers sets off up it, with the task of finding out how far the gaseous planet extends. There is great excitement, but it is dissipated somewhat when the geometer returns a few days later to say the ladder is nowhere near long enough.

For years and years sections of ladder are added, but it seems it is in vain. Each time the geometers return to say that the ladder is still not long enough.

Actually, as they ascend the ladder, both the Jeometers and the ladder itself are shrinking, shrinking so small that it is physically impossible for them to ever get to the outer surface. (At absolute zero, they will shrink to absolutely nothing.) Yet as they climb up, becoming colder and colder and at the same time smaller and smaller, the steps on the ladder, their measuring rods – everything – are also getting smaller and smaller, so they never realize the shrinking is happening. Eventually, the Jeometers decide their planet is infinitely large. Which it isn’t.

The substance of this thought experiment is to show that there is always a possibility to the effect that whatever geometry we invent, Euclidean or not, it may always fail to be the true one. In fact, “truth of geometry” is a strange expression since the statements of geometry are a matter of convention.

The geometrical axioms are therefore neither synthetic a priori intuitions nor experimental facts. They are conventions…. In other words, the axioms of geometry… are only definitions in disguise. What then are we to think of the question: Is Euclidean geometry true? It has no meaning. (Poincare, 1952)

4. Einstein vs. Maxwell

Classic electrodynamics told people this: light is a change (“oscillation”) in the electromagnetic field; and it works both ways. A change in the electric field gives rise to a magnetic field and a change in the magnetic field gives rise to an electric field. In response to this theory, (when, by the way, he was only sixteen supposedly…), Einstein thought of chasing a beam of light (oh, puberty…). The point of this chase – or “running along” – is to pinpoint impossibility: if change is essential for a light wave, then it should be so for any observer, be it a moving or at rest; but if you are moving with the exact speed c, then with respect to you, change is not coming about. Is like chasing a wave in the ocean. If your speeds are equal, then the hump of water does not change relative to you.

If I pursue a beam of light with the velocity c (velocity of light in a vacuum), I should observe such a beam of light as a spatially oscillatory electromagnetic field at rest. However, there seems to be no such thing, whether on the basis of experience or according to Maxwell’s equations.

Brilliant! (Quite literally.)

5. Heisenberg γ-ray microscope

The uncertainty principle was very much debated in the mid-twentieth century. Many philosophers knock-knock-knocking on physics door were appalled and tried their best to disprove its (a) validity, (b) importance.

For us now, it is strangely important in our taxonomy. As it happens, the thought experiment connected to this principle is not designed to refute any theory and it is subsequent to the principle itself. Could it be that it is a case of illustrative thought experiment – in Popper’s terminology?

From the first principles of quantum theory, Mr. Werner Heisenberg formally derived the principle that the product of uncertainties in present knowledge of a system is always greater or equal to a certain constant (known as Planck’s constant). “This may be expressed in concise and general terms”, Heisenberg adds, “by saying that every experiment destroys some of the knowledge of the system which was obtained by previous experiments.”

And then comes the thought experiment. Notice the new flavour: the principle had already been formally arrived at! Heisenberg himself calls this thought experiment an “example”.

As a first example of the destruction of the knowledge of a particle’s momentum by an apparatus determining its position, we consider the use of a microscope. Let the particle be moving at such a distance from the microscope that the cone of rays scattered from it through the objective has an angular opening ε. […] But, for any measurement to be possible at least one photon must be scattered from the electron and pass through the microscope to the eye of the observer. From this photon the electron receives a Compton recoil of order of magnitude h/λ. The recoil cannot be exactly known, since the direction of the scattered photon is undetermined within the bundle of rays entering the microscope. Thus there is an uncertainty of the recoil in the x-direction of amount…

Wonderful!

6. Schrodinger’s cat

Still indoors with quantum mechanics. The Copenhagen interpretation of the formalisms of quantum mechanics did not reject one (bizarre) possibility: namely that of a system being at two (superposed) states at the same time. Since we can only observe one – in other words, since for us a system is either one way or the other –this possibility remain only a theoretical one. On a philosophical level, sure, it said many things about our place in the universe: that we “create” reality, we restrict it to only one of its states, that we are doomed with only partial knowledge of the world, etc. But it remained a theoretical option nonetheless. This theoretical option however bugged many people, amongst whom Einstein of course, but als Mr. Schrödinger.

One can even set up quite ridiculous cases. A cat is penned up in a steel chamber, along with the following diabolical device (which must be secured against direct interference by the cat): in a Geiger counter there is a tiny bit of radioactive substance, so small, that perhaps in the course of one hour one of the atoms decays, but also, with equal probability, perhaps none; if it happens, the counter tube discharges and through a relay releases a hammer which shatters a small flask of hydrocyanic acid. If one has left this entire system to itself for an hour, one would say that the cat still lives if meanwhile no atom has decayed. The first atomic decay would have poisoned it. The ψ-function of the entire system would express this by having in it the living and the dead cat (pardon the expression) mixed or smeared out in equal parts.

This thought experiment seems no different from the first, classic ones. It thinks up a possible state of affairs which supposedly (a) was overlooked by quantum physicists and (b) gives rise to absurdity. It’s difficult to say here whether the absurdity is a matter of logical contradiction or otherwise “empirical”-ish. (But it’s the same with Galileo’s balls. It is mainly because of our language that we think of an object falling “both slower and faster” than another one as being a contradiction. It is, just the same, mainly because of our language that we think of a living object being “both dead and alive” as being a contradiction).

The people considered in philosophical thought experiments can get very weird: we are asked to imagine people splitting like amoebas, fusing like clouds, and so on. Stevin’s frictionless plane, or Einstein chasing a light beam are homely by comparison.

True that+

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The geometrical axioms are therefore neither synthetic a priori intuitions nor experimental facts. They are conventions…. In other words, the axioms of geometry… are only definitions in disguise. What then are we to think of the question: Is Euclidean geometry true? It has no meaning.

Poincaré, 1952, Science and hypothesis

Nevermind dilemmas

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As I was sitting in my chair
I knew the bottom wasn’t there,
Nor legs nor back, but I just sat,
Ignoring little things like that.

Comparing the incomparable

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Garssen, B. (2009). Comparing the incomparable: Figurative analogies in a dialectical testing procedure. In F. H. van Eemeren & B. Garssen, Pondering on problems of argumentation: Twenty essays on theoretical issues (pp. 133-140). Amsterdam: Springer

_______________________________________________________________________________

A short paper on analogies. The question Garssen attempts to answer is this: Is analogy a type of comparison? The answer is: no. Let’s see.

Comparison argumentation stands in the pragma-dialectical theory as one of the three types of argument schemes alongside symptomatic and causal argumentation. In general, what makes pragma-dialecticians distinguish one scheme from another is the different type of “liaison” they provide from the premise to the standpoint. Regardless of their form in natural language, the reconstructed versions of these schemes are seen as different because they elicit separate critical behaviour. More precisely, you cannot use the critical questions that go with one scheme to test the other.

Comparison argumentation goes as follows. (Notice that X & Y below can be any referable object under discussion – these are not grammatical representations).

Y is true of X

because: Y is true of Z

and: Z is comparable to X.

One variant of this scheme is called by Garssen the “extrapolation of characteristics”. His example is this:

Camera surveillance in the centre of Amsterdam will prove to be very effective, because in London, camera surveillance proved to be highly effective before.

If we twist the language a bit, we get to:

The effectiveness of surveillance is true of Amsterdam

because The effectiveness of surveillance is true of London

and London is comparable to Amsterdam.

Notice, also, that this is not a logical reconstruction. This “scheme” does not have any merits on its own, but stands as a reasonable argumentation for the standpoint if the critical questions pertaining to it are satisfactorily answered. And this is a matter of degree.

Another type of comparison scheme could be identified with respect to prescriptive standpoints. (Notice that in the example above Garssen dealt with descriptive statements – i.e. which do not have modal aspect).

His example of this second variant is this:

The European committee should grand Belgium higher agricultural subsidies because it granted Italy higher subsidies as well.

This could be reconstructed in the same manner, but notice the extra sauce: the question of the adequacy of such argument hinges on whether the two (Belgium & Italy in our case) are indeed members of the same class. In legal contexts, this boils down to checking the legal provisions. However, in one way or another, the adequacy of the scheme depends on the acceptability of the answer to the critical question: Are they indeed members of the same class?

But now what about figurative analogies?

At first glance, they seem way off the track. (Conversationally too!)

Take this one. Answering to whether USA should intervene in Korea, president Truman is said to have asked:

The best time to meet the threat is in the beginning. It is easier to put out a fire in the beginning when it is small than after it has become a roaring blaze.

Here’s Garssen’s commentary:

Fire and war clearly belong to different classes of events. That makes it impossible to compare them in a direct way. In this case we have to look for similarities, not so much between the concrete features of fire and war, but between the abstract relations within what is said in the premise and what is said in the standpoint. It I predicted that the war in Korea will become unmanageable if we do not act immediately and that is exactly the reason why we should act now. Truman does not make a direct, literal, comparison between war and fire. That is why the standard critical questions that go with comparison argumentation (are there similarities? are there differences?) do not really apply.

The reason why this path was chosen: if we really set about to test this argument in the way normal comparison schemes would require, it wouldn’t stand a chance. Fire is unlike war in every direct (read: literal) sense. However, more intuitively, fire and war are alike on a more abstract level – they are alike in a sense, as the cautious philosopher would say. Therefore, one should reveal this in his or her reconstruction.

According to Garssen we could explain this intuition as follows: “figurative analogy is not argumentation based on a comparison relation but a way of presenting another type of argument scheme” (138). In other words, it is not that it is a looser, more far-fetched, type of comparison; it is a discursive device for introducing (and supporting) a sub-standpoint. Notice, again, the structure in the Truman example:

The best time to meet the threat is in the beginning. It is easier to put out a fire in the beginning when it is small than after it has become a roaring blaze.

So,

We should go to war against Korea now/ We should not postpone our response to the war that is now developing in Korea. That is because the best time to meet the threat is in the beginning. It is like being confronted with a fire. It is easier to put it out in the beginning when it is small then after it has become a roaring blaze.

Garssen does not reconstruct this example. In fact, he doesn’t provide a full reconstruction of any of the examples. Let us try:

(1.) What happens in Korea (Y) is such that our response to it should not be delayed (X)

(1.1.) What happens in Korea (Y) is a threat (Z).

(1.1’) Threats (Z) are such that one’s response to them should not be delayed (X).

Notice that this is a case of symptomatic argumentation.

Where does our fire-analogy fit? Garssen’s answer seems to be: “Nowhere”. Because the fire-war figurative language is not part of the reconstructed argumentation. It is just a way of introducing an agreed upon starting point, namely (1.1’). So what the party really needs for his argumentation is this statement (1.1’), and the way he introduces it is by referring to a more well-known situation – or a more easily imaginable one – namely that when a fire threatens to become “a roaring blaze”. So what we have here is a case where the protagonist is urging the other party to recognize the principle (1.1’) as recognized in other, simpler, instances.

Essentialism vs. Nominalism

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Popper, K. (1983). Two kinds of definitions. In D. W. Miller (Ed.) A pocket Popper (pp. 87-101). Glasgow: Fontana Press

There are, apparently, two kinds of approaches to the act of defining: the essentialist approach and the nominalist approach. The former is something of a fairytale today – at least when it is spelled out up to its ultimate consequences. Popper undertakes to refute the former and support the latter.

The Aristotelian view of knowledge is singular in its emphasis on the importance, let’s say, induction. However, although bringing sense-data in the game, its overall structure was mainly Platonic. So there is opinion and there is knowledge. Opinion is opinion. But where does knowledge come from? One should say: sound arguments. Aristotle would agree, for it is the truth of the premises and the validity of the demonstration (syllogism) that makes a conclusion true. Sweet. The only thing is, this leads to an infinite regress: how do we establish the truth of the premises? By means of a valid syllogism from other premises found one-step-backwards in our reasoning. How do we establish the tr… well, you get the idea.

Against this infinite regress, Aristotle – again, one should say Plato – distinguished a certain type of intuition by means of which we come to know the truth of our most basic premises. (The ones which we should posit as a basis for our sciences, for instance. No wonder Aristotle saw his legacy as a constant search for these basic premises which would ultimately form an encyclopaedia of starting points). The statements we thus acquire are there in our head because we can grasp the essence of certain slices of reality. Long story short: science = essences + logic.

Of course, this view of definition is obsolete. The role of definitions in science is very different from what Aristotle had in mind. As a matter of fact, the whole thing works the other way around: we don’t ask “What is gravity?” and try to respond, but we ask “What is the force which draws unsuspended objects to earth?” and decide to respond “It is gravity”. To put it speech act theoretically, a definition is a kind of declarative speech act, not an assertive one. It cannot be true or false. That is why, contrary to popular belief, definitions don’t play a big role in science, but, as it were, in spreading science and understanding. They are, when all’s said & done, labels. (NB: to report of a definition is, however, subject to alethic assessment as any other assertive is).

Does this mean that such intuition do not exist? Not necessarily. We might have them on some psychological level or another. Popper’s claim is methodological: it simply means that they do not play a role in establishing the epistemological values of a claim. They are private.

But here’s another thing. Suppose we do stick to the importance of definitions. The problem with this choice, as correct as it may be, is that it is untenable. It cannot hold in principle: one cannot define all the term one uses in a theory because that would lead to an infinite regress. You define one term by other terms which, if you define, you produce more terms. This demand resembles the one that all our statements must be proved.

How can nominalism be a solution to that? Well, Popper goes, let’s first bust a myth:

Aristotelianism and related philosophies have told us for such a long time how important it is to get a precise knowledge of the meaning of our terms that we are inclined to believe it. And we continue to cling to this creed in spite of the unquestionable fact that philosophy, which for twenty centuries has worried about the meaning of its terms, is not only full of verbalism but also appallingly vague and ambiguous, while a science like physics which worries hardly at all about its terms and their meaning, but about facts instead, has achieved great precision. This, surely, should be taken as indicating that, under Aristotelian influence, the importance of the meaning of terms has been grossly exaggerated. 97

This is, more or less directly, a criticism towards Wittgenstein I, for which philosophy is primarily to concern itself with making the meaning of terms clear.

Roy Sorensen - Thought experiments (part 1)

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Sorensen, R. (1992). Thought experiments. New York/Oxford: Oxford University Press

Never in my (admittedly, not particularly lengthy) life have I bumped into such a remarkable mixture of immodesty and disorder. In Thought experiments, nothing seems to escape prof. Sorensen’s wit. Read “not one single thing” for “nothing”. The book is a disparate plunge into microbiology, logic, psychology, epistemology, pathology, mathematics, biology, grammar and, par Socrate!, metaphysics. To be clear: the nature of the subject matter must have made delving into the above list almost a necessity. As anyone who gave it a bit of attention will concede, thought experiments appear everywhere. But there is a big difference between discussing a type of discourse throughout more than one field and discussing a type of field throughout more than one instances of a type of discourse.

I sense (from the book as well as from some of the reviews it received) that Thought experiments was intended as a monograph. Its explicit taxonomic objective is the first clue. If so, it is an unfortunate by-product of copyright laws that the curious student will have to trudge through 300 pages of the only book with such a telling title. Whoever edited this book is equally blameworthy for not spanking out tens and tens of pages the sole purpose of which is to squash doubts about the author’s literacy. Of course, “freedom of expression” etc. OK. But if not by prohibition, may students more trained in elementary law figure out ways of blocking capital works with capital titles being written after this fashion:

Rearranging the problem this way makes the problem easier, just as it is easier for a child to eat his steak after his mother has sliced it for him.

One of the advantages of watching a movie on a VCR rather than at a theatre is that you are free to fast-forward and rewind.

Predatory birds and snakes maneuver so that their prey can be swallowed headfirst. Consumers of information display similar preferences.

If you have more than one mouse, you have mice. But houses are not hice, nor blouses blice.

When stood up against Vaihinger, Kuhn appears pale and tame. Kuhn dips his big toe into the pool of incoherence. Vaihinger belly flops.

At first glance, covert presumption precluders are as innocent as new-laid eggs.

Thus, thought experiments developed from experiments in the way a spider's spinners evolved from legs.

To close this exhaust-pipe introductory passage, I leave you with the author appearing on page 124 in a photo of superlative irrelevance to the discussion.

OK, from this point on I shall take Sorensen’s book seriously.

Two purposes could be identified as red threads guiding the book: (1) to establish true and interesting generalizations about thought experiments, (2) to offer a resolution to the problem of thought experiment’s epistemic value (rapidly, are thought experiments of any epistemic value). The first one includes (1a) a taxonomy and (1b) a reconstruction of how they work. The second one includes (2a) an explanation of the role of thought experiment in science and philosophy, (2b) an answer to the “new data” problem – “But if you just ponder, then the information you have leaving the armchair is the same as the information you had when you sat down. So how can you be better off?” (p. 76).

You may have noticed that there is no “(x) a definition” point in the above list. Sorensen does provide one but it is at page 205 and it comes after the taxonomy, after a full-blown discussion of most relevant thought experiments and after the logical reconstruction. This being the case, I shall refrain from accepting the sentences below as constituting a definition:

“A thought experiment is an experiment (see p. 186) that purports to achieve its aim without the benefit of execution.” (p. 205)

“An experiment is a procedure for answering or raising a question about the relationship between variables by varying one (or more) of them and tracking any response by the other or others” (p. 186)

Anyway, taclking (1), Sorensen posits the profitability of what he names the cleansing model of thought experiments. He opposes it to other models which, in the past, purported to have found how these scientific and philosophical machineries work. Swiftly put, the cleansing model generalizes that all thought experiments are intended to refute by reduction ad absurdum.

“The cleansing model is inspired by incidents in which you recognize your own irrationality and then change your beliefs to remove the flaw. A friend of mine was a sensitive boy who became worried about the ants that he inadvertently crushed while walking about. His father assured him that he should not worry about killing ants because "there are millions of them." This satisfied my friend for a while. But his new equinamity was terminated by a thought about the growing human population. This illustrates the familiar situation where an inconsistency takes root, is detected, and is then weeded out.

This, I believe, is a good starting point: instead of debating what is the added value of creating a story to refute a claim, Sorensen begins with the simpler and more salient feature of thought experiment. Whatever may prove to be the added value of using them, one’s inquiry should start there: they are first and foremost tools for refuting a claim.

What type of claim? And how does the tool work? To the first question, Sorensen answers: either a universal claim or a particular claim. According to this division, the thought experiments that refute a universal claim are called necessity refuters. The type of thought experiments that refute particular claims are called possibility refuters. Of course, the claims need not be neatly designed as categorical statements, but their consequence always receives the abovementioned modality.

I should probably mention here that possibility statements are not refuted in the same way necessity statements are. Since possibility statements do not prohibit the truth of any one proposition, their logical falsifiability is zero. This has nothing to do with the field in which such statements occur. Also, regardless of the logical apparatus of a thought experiment “It is possible that x” cannot be used in an argument to arrive at “It is not possible that x”.

To the second question, Sorensen lays down these steps (p. 136):

i. S Modal source statement. Fertile sources of modal propositions include semantic theses (definitions, synonymy claims, entailment theses), testability theses (unverifiability, unfalsifiability, indetectability), feasibility claims, law statements, disposition and intention attributions, validity verdicts, and clusters of these—theories.

ii. S → □ I This proposition draws the relevant modal implication from the source statement

iii. (I & C) □→ W This proposition is read as a subjunctive conditional: if I and C were the case, then W would be the case. This proposition claims that the antecedent, which is the conjunction of the implication and the imagined situation, has a weird consequence.

iv. ¬ ◊W Absurdity. This proposition explains the weirdness as an impossibility

v. ◊C Content possibility. This asserts that the content of a that the content of the thought experiment is a possibility

Again, I grant Sorensen that this is a good place to start. After all, this is nothing less than (a more detailed version) of modus tollens. However, there is a minor point: the order of a sentences. Indeed, they are inconsistent in whatever order one arranges them, and thus Sorensen’s idea that thought experiments boil down to paradoxes is not affected by my rearranging. But if modus tollens goes as follows:

p → q

¬q

Therefore, ¬p

Then I see no reason for going:

p → r

r & s → q

¬q

Therefore, ¬p

To resume: the theory p predicts that r but since we know that s could be the case, and that the conjunction of r & s yields an absurdity, we conclude to non-p. I will argue later that the 3 extra steps from Sorensen’s model are not necessary – although I see how sometimes they can be an accurate reconstruction of this or that thought experiment. For now, let us observe that in order for such an apparatus to be academically potent, the other party must (be known to accept) s. If the possibility of a certain state of affairs is not granted, no thought experiment can be constructed. For instance, to take one of Galileo’s thought experiments, if the other party does not agree that two things can be attached to form one thing (balls, stones, whatever), the thought experiment has no power to persuade. In fact, the argumentative process goes the other way around: in the opening stage, both parties agree on s (& p, & r, & whatever else is needed), and on this agreement the antagonist builds his case.

The second point to observe is that the model does not fit the definition. Remember experiments being defined (quite adequately) as fiddling with one variable to observe changes in the other? Now what exactly is one varying in the model above? Where is the observed dependency? Let’s imagine the following theory: All ravens are born in the southern hemisphere. Let us now imagine that we know how no white things can be born in the southern hemisphere. If our universal statement implies “All white ravens are born in the southern hemisphere”, we have hereby unearthed an inconsistency. Have we made any changes?

The impression I get here is that the label of “experiment” still fits these uses of discourse because the possibility of s is provisionally accepted by both parties. They take it as their starting point – regardless of whether it is a real possibility entailed by any other theory they agree upon. At the end, in the concluding stage, the protagonist can always go back to the opening stage and revise his acceptance: indeed, many Aristotelians did just that to counter Galileo’s refutation.

The third point to observe – a point which is also stressed by Martin Bunzl in his review of Sorensen’s book – is that the thought experiment and the use of thought experiment are two different objects of study. For instance, our Galilean thought experiment was used to offer (some) support to the idea that velocity is universal and (total) corroboration with the thesis that weight does not matter. But the passage from the latter to the former is incidental and certainly not deductive. Going “Aha! You are wrong” and going “Aha! I am right” are two different steps. Sorensen discusses both, alternatively without making any explicit distinction.

Let us use this model to analyse Searle’s Chinese Room. In want of any definition, I will conclude that Searle’s Chinese Room is a thought experiment simply on the grounds that it is mentioned by many theorists interested in thought experiments. I leave in suspension the question of whether this is a satisfactorily accurate statement or not.

What is the S?

Well, at first glance, it must be something around the claim that:

(S₁) Computers can think.

Notice that the chapter in which Searle presents his Chinese room (in Reith lectures) is entitled Can computers think? So it might be justified to start from S₁. However, S₁is very ambiguous and it would be unfair to Searle to leave it at that. For instance, he mentions explicitly that what we are concerned with are digital computers, that is to say, machines which manipulate symbols and nothing more. By “nothing more” Searle means something like: however much they interact with the physical world, and however much they simulate human interaction with the physical world, the machinery does not produce intentional states of mind. It cannot “have a semantics”, as he puts it. So we might want to change S₁ to

(S₂) All sufficiently advanced symbol-operators can have any mental state

Whether this is indeed what Searle’s adversaries had put forward in the past is not relevant. I am, for now, interested in cramming the Chinese Room into Sorensen’s scheme.

The next thing is to draw “the relevant modal implication”. This implication could be:

(I₁) A sufficiently advanced computer can understand Chinese

Yet again, we would like to make the implication more exact. Based on Searle’s text, we should like to say:

(I2) A sufficiently advanced symbol-operator, given proper conditions, can have the mental state of understanding Chinese

We need not nitpick: understanding here means “knowing the meaning of the sentences”. So let’s simplify, now that we know what we’re talking about:

(I3) All supercomputers in superconditions can understand Chinese.

Thus,

(I4) If it is a supercomputer in superconditions, it can understand Chinese.

Now, the man locked in the Chinese room is not a very advanced computer. That is one of the points. But as the reductio goes, Searle asks us to imagine that that is the case, or that no significant difference occurs. He wants us to suppose that the cards are very sophisticated, and that the “program” they represent is the same as in the very advanced computer the theory is referring to. Indeed, computers are just that: “people” that manipulate “cards” really well and fast. Historically, anyway, this is in fact very precise.

But what would C be?

Now, modus ponens:

(I & C) □→ W: All supercomputers in superconditions can understand Chinese & Searle is a supercomputer in superconditions, therefore Searle understands Chinese.

Now:

(¬ ◊W): Searle does not understand Chinese

Therefore?

This doesn’t make much sense. I mean, it does, but it is too stupid. Searle’s conclusion is that computers cannot think, this is what he explicitly claims to tackle, so the contradictory of (S), something like:

(¬S) No sufficiently advanced computer can have any mental state whatsoever.

Is Searle’s argument so blatantly invalid? Note that the reconstruction above is also the reconstruction made by Damper’s (2006) The logic of Searle’s Chinese argument. The step from (¬ ◊W) to ¬S is always invalid because I & C are less general then S. So, unless some sort of inductive step slips in the scene, all thought experiments (reconstructed by Sorensen’s scheme) which conclude to the opposite of S are invalid. Let me re-state it so that it is clear. By “supercomputer” I mean “very advanced digital symbol operator”. By “supercircumstances” I mean the Chinese Room scenario. (S) is what “strong Artificial Inteligence claimed. The rest has been discussed:

(S) All supercomputers in supercircumstances can have any mental state

(S → □I) If [All supercomputers in superconditions can have any mental state], then [All supercomputers in superconditions can understand Chinese].

(◊C) Let us suppose that Searle is a supercomputer in superconditions.

((I & C) → W) If all supercomputers in superconditions understand Chinese and Searle is a supercomputer in superconditions, then Searle does understand chinese.

¬◊W Searle cannot understand Chinese

Therefore

(¬S) No supercomputers in supercircumstance can have any mental state

This is invalid. And simplified. And, I believe, wrong as a reconstruction.

Galileo really kicked the bucket

2011-10-04T00:16:00.001+03:00