Mind, Body, World- Foundations of Cognitive Science, 2013a

instance, meaningful, complex tokens are possible because the semantics of such
expressions are defined in terms of the contents of their constituent symbols as well
as the structural relationships that hold between these constituents. The cognitive
vocabulary’s exploitation of constituent structure leads to the systematicity of classical
theories: if one can process some expressions, then it is guaranteed that other
expressions can also be processed because of the nature of constituent structures.
This in turn permits classical theories to be productive, capable of generating an
infinite variety of expressions from finite resources.
Some classical theorists have argued that other approaches in cognitive science
do not posit the structural relations between mental contents that are captured
by the cognitive vocabulary (Fodor & Pylyshyn, 1988). For instance, Fodor and
Pylyshyn (1988) claimed that even though connectionist theories are representational,
they are not cognitive because they exploit a very limited kind of relationship
between represented contents.
Classical theories disagree with Connectionist theories about what primitive
relations hold among these content-bearing entities. Connectionist theories
acknowledge only causal connectedness as a principled relation among nodes;
when you know how activation and inhibition flow among them, you know everything
there is to know about how the nodes in a network are related. (Fodor and
Pylyshyn, 1988, p. 12)
As a result, Fodor and Pylyshyn argued, connectionist models are not componential,
nor systematic, nor even productive. In fact, because they do not use a cognitive
vocabulary (in the full classical sense), connectionism is not cognitive.
Related arguments can be made against positions that have played a central
role in embodied cognitive science, such as the ecological approach to perception
advocated by Gibson (1979). Fodor and Pylyshyn (1981) have argued against the
notion of direct perception, which attempts to construe perception as involving the
direct pick-up of information about the layout of a scene; that is, acquiring this
information without the use of inferences from cognitive contents: “The fundamental
difficulty for Gibson is that ‘about’ (as in ‘information about the layout in
the light’) is a semantic relation, and Gibson has no account at all of what it is to
recognize a semantic relation” (p. 168). Fodor and Pylyshyn argued that Gibson’s
only notion of information involves the correlation between states of affairs, and
that this notion is insufficient because it is not as powerful as the classical notion of
structural relations among cognitive contents. “The semantic notion of information
that Gibson needs depends, so far as anyone knows, on precisely the mental representation
construct that he deplores” (p. 168).
It is clear from the discussion above that Pylyshyn used the cognitive vocabulary
to distinguish classical models from connectionist and embodied theories. This
does not mean that he believed that non-classical approaches have no contributions
Marks of the Classical? 353