Functionalism (philosophy of mind)

Functionalism is a term in philosophy developed as an answer to the mind-body problem because of perceived lack of success exhibited by both identity theorists[?] and logical behaviourists[?].

Functionalism's explanation of consciousness, or the mental, is best understood when considering the analogy made by functionalists between the mind and the modern digital computer. More specifically, the analogy is made to the machine that the Church-Turing thesis posits is capable of in principle computing any given algorithm (the algorithm must have certain limitations though); namely the Turing machine. A Turing machine must possess certain characteristics:

1. Data input (analogous to the senses in humans).
2. Data output (analogous to both behaviour and memory).
3. Functional states (analogous to mental states),
4. The ability to move from one functional state into another.
5. The definition of functional states with reference to the part they play in the operation of the entire entity - ie. in reference to the other functional states.