Discussion of the Full Description Problem

Click here to respond to this discussion regarding the Full Description Problem.

Some Results (?) of our Discussion of Smart

A. The Idea (Ideal) of a Full Description:

A full description of a person (S) at a time (t) would be a complete list of all the properties instantiated by S at t.


B. The Full Description Problem:

Mental states and processes seem to be (must be?) something over and above physical states and processes, since a full description of a person at a time would require that we list not only physical properties but also mental properties.


C. Type-Type Identity:

"A=B" is a true expression of type-type identity iff the set picked out by the term "A" is coextensive with the set picked out by the term "B."


D. The Type-Type Identity Thesis (TTIT):

Mental states are type-type identical with physical states. That is, every mental predicate (M) picks out a set of states or processes which is coextensive with a set picked out by a physical predicate(P).


E. TTIT yields a solution to the Full Description Problem:

Suppose that we have a complete list of the physical properties of S at t. Suppose further that TTIT is true. We then know that if S instantiates any mental properties then those properties are already represented on the list of physical properties, The complete physical description of S at t would thus include as a subset a complete mental description of S at t.


F. The Multiple Instantiation Problem:

Mental states can be instantiated in a wide variety of different physical systems. Not only human being but dogs, octopi, and (in principle at least) silicon-based aliens can, e.g., experience pain. It is thus overwhelmingly unlikely that there is some identifiable class of physical events (e.g., C fiber firing) that is type-type identical with the class of mental events of a certain type (e.g., pain).


G. Some questions:

1. Would token-token identity thesis provide a solution to the full description problem?

2. Would a species-relative type-type identity thesis provide a solution to the full description problem?

3. Could TTIT itself be retained in the face of the multiple instantiation problem simply by identifying the set of (e.g.) pain states with a massively disjunctive set of physical states?

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