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This text is an introduction to the concept of teleosemantics, which combines success semantics and design thinking to understand representation in terms of achieving specific results in certain circumstances. It explores the relationship between success semantics and broadness, mental causation, and design thinking.
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Teleosemantics without Tears David Papineau (Kings College London) Minds without Magic Bielefeld September 2013
Introduction Teleosemantics combines two ideas, neither of which strikes me as at all contentious. Success semantics: representation is a matter of vehicles guiding behaviour which will produce results given certain circumstances. Design thinking: representation needs to be understood in terms of the design of such success-semantical systems.
Success Semantics We have success semantics whenever something takes a vehicle V to represent C, in the sense that V leads it to behave B in a way that is appropriate given C, from the point of view of achieving R. This is a very flexible idea: signalling involving multi-agent and sub-personal systems, as well as persons; general means-end facts as well as particular ones; inferential systems whose salient result R is itself to produce representations; compositional representational systems . . .
Success Semantics and Broadness Success semantics is environment-involving. By attributing content, we view the system as embedded in a wider environment: it will achieve distal result R, when distal condition C obtains. From this perspective it is quite unsurprising that ‘contents should be broad’.
Success Semantics and Fodor Fodor finds such broadness puzzling, because he is thinking of representation as something that captures how vehicles ‘push out’ behaviour from the inside. But this is not the right way to start thinking about representation.
Success Semantics and Mental Causation One problem about mental causation is: how can role properties be causally efficacious? And perhaps the right answer is—they can’t. Only their realizers do (cf Lewis and Kim). But this doesn’t really address the issue of how can content properties cause (given that they are broad)?
Success Semantics and Mental Causation The answer is that content doesn’t cause per se (though it might seem to cause behaviour (I’ll come back to this))—but truth does—it causes success (distal results R). But if truth is ‘that property in beliefs that causes success’, how can it cause success? (Godfrey-Smith.) This looks like ‘solubility’ causing dissolving, or ‘dormitive virtue’ causing sleeping.
Success Semantics and Mental Causation Here we can pull the Lewis-Kim trick once more. It’s not the truth per se that does the causing, but its more specific realizers. I have the desire for ice-cream. I succeed in getting it. How come? Well, I believe that ice-cream is in the fridge, and so go there, and, moreover, ice-cream is in the fridge . . . Here it is the conjunction of (a) my acting on a certain belief and (b) a certain fact obtaining (ice-cream is in the fridge) that causes my getting the ice-cream. The combination of this belief with this fact is one way for a belief to be true, so to speak (the combination, that is, of the belief that ice-cream is in the fridge with the fact that ice-cream is in the fridge).
Success Semantics and Mental Causation Tarski defines the property of truth as a disjunction of such combinations. (X is true iff (X = bel1 and fact1) OR (X = bel2 and fact2) OR . . .) From this perspective we can regard truth as a higher-order property, which is realized by these more specific disjuncts. Now truth might be disqualified from causal efficacy by its higher-order status. Still, even if the property of truth isn’t itself causally efficacious, we can view the word ‘true’ as naming in context something that is causally efficacious, namely the combination of (a) having a belief with a specific truth condition and (b) the fact that makes this belief true. These two things do together cause something—viz the distal result R that the action is aimed at.
Design Thinking Note that nothing in success semantics invokes design (let alone design understood aetiologically). Why does teleosemantics want to add this in? Well, this will be compulsory if you are interested in the (very interesting) question of why representing systems are structured as they are. But isn’t cognitive science primarily interested in the what, not the why, of representing structures?
Design Thinking—Reducing Indeterminacy One argument is that success semantics leaves it open what results R we see interpreting systems (and in particular desires) to be aiming at. (CfStalnaker’s indeterminacy). If we fix on those Rs that these systems have been aetiologically designed to produce, then that will eliminate this indeterminacy (-ish). But I am not sure how far this serves. Couldn’t an insistent anti-aetiologist (Paul Griffiths) insist that he’s not fussed about why we fix on certain Rs?—it’s enough that we have structures that will guarantee the achievement of such-and-such Rs if B is prompted by V and C obtains.
Design Thinking in General Let us ask why it is ever helpful to ascribe selectional/design properties to something (it’s a thermostat, carburettor, heart, wing, . . .). Here we are identifying items essentially in terms of what they are supposed to do. We often invoke such properties in apparently causal explanations (the room is cool because I set the thermostat low, his pulse rate is up because his heart is beating fast . . .) Why so? How can these historical properties matter causally?
Design Thinking in General In such cases we are often pretty ignorant of the precise mechanism involved—rather we refer to it simply as ‘some mechanism that has been designed to do such-and-such’ (cut the heating circuit, circulate the blood). It is largely via knowledge of design that we have some grasp of the mechanism’s causal powers, which is why identifying the mechanism via its design properties plays an essential role in explanation.
Design Thinking in Psychology I’d say that similarly we have a very limited direct grasp of psychological mechanisms. What we know of them comes via our knowledge that they are designed to cause such-and-such ends R, and more specifically involve states V that are designed to generate behaviours that will achieve those ends if such-and-such conditions C obtain. That ‘s why we use design properties to characterise the mechanisms that we invoke in psychological explanations. (Of course, these design properties don’t themselves make a difference to the current causal powers of our psychological states. But that doesn’t mean that they aren’t our best way of characterizing those states.)
Design Thinking—Syntax and Semantics Design thinking is particularly important to mechanisms that involve representation, in a way that is not always appreciated. When we posit a system involving causally interacting representational vehicles, we do so by presupposing that they will interact in the way that they are supposed to, given their semantics. The syntactically actual inferences will (mostly) be the semantically valid ones. (The point is familiar, but is often obscured by Dennett’s spurious contrast between the intentional and design stances. (Dennett is probably right to suggest that we should view ‘folk belief-desire psychology’ instrumentally. But an instrumentally viewed theory about causal structure is still a theory about causal structure.))
Design Thinking Still Dispensable? Someone like Paul Griffiths might continue to insist that the design stance is just a heuristic device, rather than something that locks onto the essence of representation? (We can always take what the design heuristic tells us about the causal current mechanisms, and throw away the history.) But why take this view? Any actual representational mechanism will always have a design history (and moreover we will only know about the causal structure of that mechanism courtesy of our knowledge of that history).
Design Thinking Vindicated We have two kinds: a certain sort of causal structure, and that sort of causal structure with a design aetiology. In the actual world these two kinds are co-extensive, even though in principle they could dissociate. Anybody who is interested in the former kind has to be interested in the latter kind too. That seems to me enough to warrant a teleosemantic account of representation.
