Informational Semantics
Informational
semantics is an attempt to ground meaning -- as this is understood
in the study of both language and mind -- in an objective,
mind (and language) independent, notion of information. This effort
is often part of a larger effort to naturalize INTENTIONALITY and thereby
exhibit semantic -- and, more generally, mental -- phenomena
as an aspect of our more familiar (at least better understood) material world.
Informational semantics locates the
primary source of meaning in symbol-world relations (the symbols
in question can occur either in the language of thought or in a
public language). The symbol-world relations are sometimes described
in information-theoretic terms (source, receiver, signal, etc.)
and sometimes in more general causal terms. In either case, the
resulting semantics is to be contrasted with conceptual role (also
called procedural) semantics, which locates meaning in
the relations symbols have to one another (or, more broadly, the
way they are related to one another, sensory input, and motor output).
Because on some interpretations of information, the information
a signal carries is what it indicates about a source, informational semantics
is sometimes referred to as indicator semantics. The concept
of information involved is inspired by, but is only distantly related
to, the statistical construct in INFORMATION THEORY (Dretske 1981).
The word "meaning" is
multiply ambiguous. Two of its possible meanings (Grice 1989) are:
(1) nonnatural meaning -- the sense in which the
word "fire" stands for or means fire; and (2) natural meaning -- the way
in which smoke means (is a sign of, indicates) fire. Nonnatural
meaning has no necessary connection with truth: "Jim has
the measles" means that Jim has the measles whether or
not he has the measles. Natural meaning, on the other hand, requires
the existence of the condition meant: if Jim doesn't have
the measles, the red spots on his face do not mean (indicate) that
he has the measles. Perhaps all they mean is that he has been eating
too much candy. Natural meaning, what one event indicates about
another, is taken to be a relation between sign and signified that
does not depend on anyone recognizing or identifying what is meant. Tracks
in the snow can mean there are deer in the woods even if no one
identifies them that way -- even if they do not mean that to anyone.
Information, as this is used in informational
semantics, is akin to natural meaning. It is an objective (mind-independent)
relation between a sign or signal -- tracks in the snow, for
instance -- and what that sign or signal indicates -- deer
in the woods. The information a signal carries about a source is
what that signal indicates (means in a natural way) about
that source. Informational semantics, then, is an effort to understand
non-natural meaning -- the kind of meaning characteristic
of thought and language -- as arising out of and having its
source in natural meaning. The word "meaning" will
hereafter be used to refer to nonnatural meaning; "information" and "indication" will
be reserved for natural meaning.
Informational semantics takes the
primary home of meaning to be in the mind -- as the meaning
or content of a thought or intention. Sounds and marks of natural
language derive their meaning from the communicative intentions
of the agents who use them. As a result, the information of primary
importance to informational semantics is that occurring in the brains
of conscious agents. Thus, for informational semantics, the very
existence of thought and, thus, the possibility of language depends
on the capacity of systems to transform information (normally supplied
by perception) into meaning .
Not all information-processing systems have this capacity. Artifacts
(measuring instruments and computers) do not. To achieve this
conversion, two things are required. First, because meaning is fine
grained (even though 3 is3
27, thinking or saying that x = 3 is
not the same as thinking or saying that x = 327) and information is coarse grained
(a signal that carries the information that x = 3 necessarily carries
the information that x = 327), a theory of meaning must specify
how coarse grained information is converted into fine grained meaning.
Which of the many pieces of information an event (normally) carries is
to be identified as its meaning? Second, in order to account for the
fact that something (e.g., a thought) can mean (have the content) that
x = 3 when x 
3, a way must be found to
"detach" information from the events that normally carry it so that
something can mean that x = 3 when it does not carry this information
(because x 3).
One of the strategies used by some
(e.g., Dretske 1981, 1986; Stampe 1977, 1986) to achieve these results
is to identify meaning with the environmental condition with which
a state is, or is supposed to be, correlated. For instance, the
meaning of a state might be the condition about which it is supposed to
carry information where the "supposed to" is understood
in terms of the state's teleofunction. Others -- for
example, Fodor (1990) -- reject teleology altogether and identify
meaning with the sort of causal antecedents of an event on which
other causes of that event depend. Still others -- for example, Millikan
(1984) -- embrace the teleology but reject the idea that the
relevant functions are informational. For Millikan a state can mean M without
having the function of carrying this information. By combining teleology
with information, informational semantics holds out the promise
of satisfying the desiderata described in the last paragraph. Just
as the pointer reading on a measuring instrument -- a speedometer,
for example -- can misrepresent the speed of the car because
there is something (viz., the speed of the car) it is supposed to
indicate that it can fail to indicate, so various events in the
brain can misrepresent the state of the world by failing to carry
information it is their function to carry. In the case of the nervous system,
of course, the information-carrying functions are not (as with artifacts)
assigned by designers or users. They come, in the first instance,
from a specific evolutionary (selectional) history -- the
same place the heart and kidneys get their function -- and,
in the second, from certain forms of learning. Not only do information-carrying
functions give perceptual organs and the central nervous system
the capacity to misrepresent the world (thus solving the second
of the above two problems), they also help solve the grain problem.
Of the many things the heart does, only one, pumping blood, is its
(biological) function. So too, perhaps, an internal state has the
function of indicating only one of the many things it carries information
about. Only one piece of information is it supposed to carry. According
to informational semantics, this would be its meaning.
Informational semantics -- as
well as any other theory of meaning -- has the problem of
saying of what relevance the meaning of internal states is to the
behavior of the systems in which it occurs. Of what relevance is
meaning to a science of intentional systems? Is not the behavior
of systems completely explained by the nonsemantic (e.g., neurobiological
or, in the case of computers, electrical and mechanical) properties
of internal events? This question is sometimes put by asking whether, in
addition to syntactic engines, there are (or could be) semantic engines.
The difficulty of trying to find an explanatory role for meaning
in the behavior of intentional (i.e., semantic) systems has led
some to abandon meaning (and with it the mind) as a legitimate scientific construct
(ELIMINATIVE MATERIALISM), others to regard
meaning as legitimate in only an instrumental sense (Dennett 1987),
and still others (e.g., Burge 1989; Davidson 1980; Dretske 1988;
Fodor 1987; Kim 1996) to propose indirect -- but nonetheless
quite real -- ways meaning figures in the explanation of behavior.
See also
Additional links
-- Fred Dretske
References
Burge, T. (1989). Individuation and causation
in psychology. Pacific Philosophical Quarterly 70:303-322.
Davidson, D. (1980). Essays on Actions
and Events. Oxford: Oxford University Press.
Dennett, D. (1987). The Intentional Stance. Cambridge,
MA: MIT Press.
Dretske, F. (1981). Knowledge and the
Flow of Information. Cambridge, MA: MIT Press.
Dretske, F. (1986). Misrepresentation. In R.
Bogdan, Ed., Belief. Oxford: Oxford University Press,
pp. 17-36.
Dretske, F. (1988). Explaining Behavior. Cambridge,
MA: MIT Press.
Fodor, J. (1987). Psychosemantics: The
Problem of Meaning in the Philosophy of Mind. Cambridge,
MA: MIT Press.
Fodor, J. (1990). A Theory of Content
and Other Essays. Cambridge, MA: MIT Press.
Grice, P. (1989). Studies in the Way of
Words. Cambridge, MA: Harvard University Press.
Kim, J. (1996). Philosophy of Mind. Boulder,
CO: Westview Press.
Millikan, R. (1984). Language, Thought,
and Other Biological Categories. Cambridge, MA: MIT Press.
Stampe, D. (1977). Towards a causal theory of
linguistic representation. In P. French, T. Uehling, and H. Wettstein,
Eds., Midwest Studies in Philosophy 2. Minneapolis:
University of Minnesota Press, pp. 42-63.
Stampe, D. (1986). Verificationism and a causal
account of meaning. Synthèse 69:107-137.
Further Readings
Barwise, J., and J. Perry. (1983). Situations
and Attitudes. Cambridge, MA: MIT Press.
Block, N. (1986). Advertisement for a semantics
for psychology. In Midwest Studies in Philosophy, vol.
10. Minneapolis: University of Minnesota Press, pp. 615-678.
Fodor, J. (1984). Semantics, Wisconsin style. Synthèse 59:231-250.
Israel, D., and J. Perry. (1990). What is information?
In P. Hanson, Ed., Information, Language, and Cognition. Vancouver:
University of British Columbia Press, pp. 1-19.
Lepore, E., and B. Loewer. (1987). Dual aspect
semantics. In E. Lepore, Ed., New Directions in Semantics. London:
Academic Press.
Papineau, D. (1987). Reality and Representation. Oxford:
Blackwell .
Copyright © 1999 Massachusetts Institute of Technology