Concepts,
it is said, are the vehicles of thought—the basic building blocks of our mental
lives. But what exactly are concepts? In Furnishing the Mind Jesse Prinz
formulates an impressive new theory of the nature of mental concepts. It is too early to tell whether his theory
is thoroughly successful, but he has doubtless developed an interesting and
important theory of concepts that will remain at the forefront of the concepts
debate for some time. Prinz’s
sensitivity to the nuances of both philosophical argument and psychological
data results in a superb example of the complexity and sophistication that can
be achieved in cognitive science at its interdisciplinary best.

Prinz’s
book is written for scholars in philosophy and the cognitive sciences. Although the first three chapters that
survey the contemporary debate about concepts are very readable and do not
presuppose any prior acquaintance with the debate, the uninitiated would find
the remaining chapters rather difficult to follow.

The first three chapters of the book
survey the major philosophical and psychological theories of concepts and the
standard problems facing each of them. 
Prinz tells us that some philosophers (e.g., Aristotle, Locke, Berkeley)
thought that concepts were mental images. 
Imagism provides a straightforward explanation of how concepts are
acquired perceptually, but it seems that we possess many concepts (e.g.,
justice, truth, democracy) that have no corresponding perceptual images. Other philosophers (e.g., Plato) have
thought that concepts can be identified with sets of necessary and sufficient
conditions that define the concepts in question. Bachelor, for example, can be defined as ‘unmarried male.’ Although this view has had a long and
popular career in philosophy, very few concepts can be given adequate definitions. Moreover, people do not seem to rely upon
definitions while acquiring concepts or forming categorization judgments.

Prinz also describes three
psychological theories of concepts that have been widely discussed in recent
decades: the prototype theory, the exemplar theory, and the theory theory. According to the prototype theory,
information about categories is stored as representations of the average or
most typical instances of those categories. 
An encountered object is judged to belong to a category if its
representation is more similar to the prototype representation of that category
than to any other. Prototype theory can
explain many facts about how ordinary subjects think about various categories
and their instances, but it seems to have difficulty explaining how we are able
to reason about atypical instances of certain categories and how people can
possess the same concept if they do not always form the same prototype
representation.

According to the exemplar theory,
concepts are not stored as representations of typical or average members of
certain categories. Rather,
representations of particular encountered instances are stored. Although exemplar theory can explain certain
facts about categorization, it has difficulty explaining how we can possess
concepts whose instances we have not experienced and how people can possess the
same concept if they do not store the same exemplars. According to the theory theory, concepts are mini-theories. Concepts are sets of explanatory principles
for making sense of different aspects of the world. If concepts are theories, the theory theory can explain why
possession of a concept always seems to be accompanied by certain kinds of
theoretical knowledge. But if theories
are themselves composed of concepts, serious problems face the identification
of concepts with theories.

Prinz aims to develop a theory that:

a) avoids the difficulties facing the
dominant philosophical and psychological theories of concepts;

b) preserves the strengths of the
dominant philosophical and psychological theories of concepts;

c) comports well with and explains
important philosophical intuitions about the nature of concepts; and

d) comports well with and explains
important psychological data concerning categorization.

In short,
Prinz’s rather ambitious goal is to formulate a better theory of concepts than
has ever been formulated before.

In an age where nativism about
concepts (i.e., the view that many concepts are innate) is taken as an
indisputable given, Prinz defends a version of ‘concept empiricism’—the view
that all concepts are perceptually derived. 
According to Prinz’s theory, which he calls ‘proxytype theory,’ concepts
are copies of perceptual representations that are stored in long-term memory
and can be activated in working memory. 
Prinz (pp. 150, 189) writes,

Tokening
a proxytype is generally tantamount to entering a perceptual state of the kind
one would be in if one were to experience the thing it represents…. [T]hinking is a matter of redeploying
perceptual representation off-line.

Since one would
enter into one sort of perceptual state when experiencing a prototypical member
of a category and a different sort of perceptual state when experiencing an
atypical member of a category, different kinds of proxytypes will be
constructed in working memory on different occasions. Context will determine which proxytypes get activated. Sometimes it will be best if a proxytype
represents the general tendency of a category (i.e., a prototype); at other
times a unique, perhaps atypical proxytype (i.e., an exemplar) may be
best.

Leading psychological theories of
concepts focus on only one kind of mental representation that can be called up
on the basis of stored information. 
However, perceptually derived long-term memory networks encode a wide
variety of information about perceived objects. These networks can give rise to many different representations
for a single category that can function in working memory. By claiming that concepts should be
identified with the full range of these representations, Prinz is able to
incorporate the strengths of each of the leading theories of concepts into a
single account of concepts.

Prinz’s claim that all human
concepts are copies (or combinations of copies) of perceptual representations
may sound as if it is incompatible with any form of nativism about concepts,
but he claims this is not so. Prinz
defends a weak form of antinativism but allows for the possibility that some
perceptual representations may be innate. 
Because of the widespread acceptance of various forms of nativism,
antinativist arguments do not strike many contemporary researchers as very
plausible. As Prinz (p. 189) says,
“Cognitive science was born out of arguments for nativism.” Consequently, Prinz does not want to make
his concept empiricism rely upon antinativist arguments. Instead, he tries to motivate his position
by appealing to its explanatory power.

A key explanatory virtue of
proxytype theory is that it obviates the need to postulate separate mental
representations for perception and cognition. 
Prinz thinks that, “Once we have postulated a certain class of
representations for a theory of perception, it is cost effective to see whether
those same representations can be used in a theory of cognition” (p. 122). This part of Prinz’s work is a development
of the ideas of Lawrence Barsalou.

Prinz’s
book is sometimes challenging to read because of the amount of time he spend
contrasting his own view with others and because of the amount of empirical
information he includes in his exposition. 
He wants to show that proxytype theory overcomes the weaknesses of other
theories of concepts, that it comports well with a wide variety of
psychological data, and that it can be defended against a range of standard
objections to empiricist theories. In
order to accomplish all of this in a single book, Prinz does not simply spell
out his own theory. He introduces his
theory one part at a time, dialectically playing each part off of other
possible positions. Prinz’s explanatory
strategy requires a lot of concentration on the part of the reader, but it is
well worth the effort. I highly
recommend his book to anyone engaged in research on concepts.

 

©
2002 James R. Beebe

 

James R. Beebe teaches
philosophy at Louisiana State University. 

 

Link: Jesse Prinz
home page

Categories: Philosophical