Introduction to Philosophy

9 April 2001

I. Functionalism

A. Functional systems

1. Examples of functional systems: screwdrivers, benches, carburetors

2. The essence of a functional system is its function (not its physical constitution). Function is a matter of connections between inputs and outputs

B. Turing Machines

1. Any device whose behavior can be understood in terms of a machine table. A machine table is a chart (or combination of charts) establishing three-way relationships between states, inputs, and outputs.

2. Functionalism: minds are Turing machines.

3. The relevant states are mental states (e.g., beliefs, desires, pain, etc.); inputs are effects on the body (e.g., light hitting the retina, sound waves hitting the timpanic membrane, etc.); outputs are behavior/state-transition combinations (e.g., taking a drink of water and quenching your feeling of thirst, etc.)

C. Multiple Realizability

1. Problem for Mind/Brain Identity Theory: creatures with utterly different physical constitutions could have the same mental states (mental states are multiply realizable).

2. No problem for Functionalism: whatever its physical constitution, if the creature has states that mediate in the right way between inputs, outputs, and other states, then it has a mind.

3. Multiple realizability is a major advantage for Functionalism over Identity theories.

II. Nagel, “What is it Like to be a Bat?”

A. The subjective character of experience

1. Definition: For you to be conscious is for there to be something it is like to be you.

2. Consciousness is essentially connected to a “point of view”

3. We cannot imagine what it is like for a bat to be a bat; at best we can imagine what it would be like for us to be a bat.

B. Physicalist accounts of the mind are objective

1. They embody no particular point of view

2. We cannot understand the essentially subjective in purely objective terms

C. The appearance/reality distinction

D. Frank Jackson’s example of Mary, the brilliant scientist