Dretske’s theory of representation
Philosophy 135 (04–17–2007)
The project: To say how one could make a representation out of non- representational ingredients. (So, no appeal to “interpreters” or “interpretation.”)
Design specification: “As represent Bs”
an intensional context. The following sentences must be compatible:
As represent Bs. Bs are Cs. As do not represent Cs.
possibility of misrepresentation. The following sentences must be compatible:
As represent Bs. There are As. There are no Bs.
Indication: As indicate Bs iff whenever there’s an A, there’s guaranteed to be a B. (lawlike correlation)
- Dretske uses “information” synonymously with “indication.”
- Whether As indicate Bs is relative to the circumstances: for example, in circumstances when there are no strong magnets nearby, the direction of the compass needle indicates the direction of the (magnetic) north pole.
- Whether As indicate Bs is not relative to our interests or purposes. So, the volume of a paper clip indicates the temperature, just as the height of a mercury column does.
- The same thing can indicate many different things. The altimeter on an airplane indicates both air pressure and altitude.
- Indication is intensional. The compass needle indicates the direction of the NP, but not the direction of the nearest wild polar bears, even though the NP = the direction of the nearest wild polar bears.
Indication is not representation, for two reasons:
- It is too “indeterminate”: the altimeter indicates both air pressure and altitude.
- There is no such thing as misindication (indication is like Grice’s “natural meaning”: “X means Y” entails Y.).
Functions. We could solve the problem of misrepresentation if we had functions.
- As represent Bs = it is the function of As to indicate Bs.
- The problem is that the functions of artifacts can only be understood as imposed by us (thinkers). This violates our original constraint: we can’t appeal to interpreters in our recipe for representations. We need…
Natural functions. Are there functions “in the world” that don’t depend on our purposes?
- Functions due to evolution (natural selection): function of heart is to pump blood = the reason (explanation) the heart was selected for was that it pumped blood. (Millikan)
- Functions due to ontogenesis (learning): function of Ss is to indicate Bs = the reason (explanation) the As were recruited to play a part in the control structure of the organism was that they indicated Bs.