Jean-marc pizano If (to put the point a littledifferently) their non-mental objects can‘t distinguish thoughts, how can MOPS distinguish thoughts if they are nonmental too? It’s as though the arithmetic difference between 3 and 4 could somehow explain the psychological differencebetween thinking about 3 and thinking about 4.
That red things are what instantiate redness is a truism, so you can have it for free. But Frege can’t have it for free that, although same denotation doesn’t mean same mental state, same MOP does. That must depend on some pretty deepdifference between the object of thought and its vehicle. Offhand, the only difference I can think of that would do the jobis ontological; it requires MOPs to be individuated by their roles as causes and effects of mental states, and hence tothemselves be mental. So I think we should worry about why there’s only one way to grasp a MOP even though I quiteagree that we shouldn’t worry about why there’s only one way to instantiate a property.
Well, then, that’s pretty much it for the background theory. All that remains is to add that in for a penny, in for a pound; having gone as far as we have, we might as well explicitly assume that MOPs are mental representations. That,surely, is the natural thing to say if you’re supposing, on the one hand, that MOPs are among the proximaldeterminants of mental processes (as per Thesis Five) and that mental processes are
computations on structured mental representations (as per Thesis Two). It’s really the basic idea of RTM that Turing’s story about the nature of mental processes provides the very candidates for MOP-hood that Frege’s story about theindividuation of mental states independently requires. If that’s true, it’s about the nicest thing that ever happened tocognitive science.
So I shall assume that it is true. From here on, I’ll take for granted that wherever mental states with the same satisfaction conditions have different intentional objects (like, for example, wanting to swallow the Morning Star andwanting to swallow the Evening Star) there must be corresponding differences among the mental representations thatget tokened in the course of having them.
Now, finally, we’re ready to get down to work. I’m interested in such questions as: ‘What is the structure of the concept DOG?’ Given RTM as the background theory, this is equivalent to the question: ‘What is the MOP in virtue ofentertaining which thoughts have dogs as their intentional objects?’ And this is in turn equivalent to the question:‘What is the structure of the mental representation DOG?’
2 Unphilosophical Introduction: What Concepts
Have to Be
This is a book about concepts. Two of its main theses are:
—that if you are going to run a representational/computational theory of mind (that is, any version of RTM; see Chapter 1) you will need a theory of concepts.
—that none of the theories of concepts that are currently taken at all seriously either in cognitive science or in philosophy can conceivably fill the bill.
To argue this, I shall first need to say what bill it is that needs to be filled. That’s the burden of this chapter. I want to set out five conditions that an acceptable theory of concepts would have to meet. Several chapters following this onewill be devoted to making clear by how much, and for what reasons, current theories of concepts fail to meet them.
A word about the epistemic status of the conditions I’m about to endorse: I regard them as fallible but not negotiable. Not negotiable, that is, short of giving up on RTM itself; and RTM remains the only game in town, even after all theseyears. In effect, I’m claiming that these constraints on concepts follow just from the architecture of RTMs togetherwith some assumptions about cognitive processes and capacities which, though certainly contingent, are none the lesshardly possible to doubt. (I mean, of course, hardly possible to doubt really, not hardly possible to doubtphilosophically.) If this is indeed the status of these constraints, then I think we had better do what we can to constructa theory of concepts that satisfies them.