Searle's Problem and Fodor's Problem

[Stevan Harnad]

Searle's Problem vs. Fodor's Problem

Both the symbolic (S) and the connectionistic (C) approaches to modeling
the mind seem to suffer from their own respective fatal handicap:

S suffers from Searle's Problem: Symbols have no intrinsic meaning,
they're ungrounded; their meanings are parasitic on the meanings in our
heads, which clearly do have intrinsic meaning.

C suffers from Fodor's Problem: Connectionist "representations" lack
systematicity, unlike the meanings in our heads, which clearly do have
systematicity.

My proposal is a very particular kind of hybrid approach in which C is
given only the limited and nonrepresentational role of feature
learning, a role to which it is naturally suited. The need for
systematicity (Fodor's Problem) never arises for C. S then enters as a
DEDICATED symbol system (one whose primitive symbol-tokens have
additional nonsymbolic constraints on them). The nonsymbolic
constraints are what GROUND S (thereby avoiding Searle's Problem)
through the connections between the primitive symbol tokens and the
feature-detectors that pick out the objects to which they refer from
their sensory projections.

The question of learning and learnability is clearly critical in all
this. Fodor is satisfied with a radical nativism for most of our
concepts. That's not surprising, because he accepts the "vanishing
intersections" argument against the existence of critical features
(especially sensory ones) that pick out objects. I think C may allow
the first actual TEST of whether feature intersections really vanish; I
don't think that is decidable from the armchair. In any case, whether
feature-learning took place during evolution or takes place during the
lifetime of an organism does not much matter (the answer is probably
that there is some of each). What matters is whether features are
learnable at all. I'm still betting they are, and that our sensory and
conceptual categories are not just "Spandrels."

Stevan Harnad
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