Functionalism in Philosophy of Mind: Mental States and Causality
III. Functionalism
Functionalism in the Philosophy of Mind attempts to solve the problems of recognizing and classifying mental states. It’s a realistic position, meaning it asserts the existence of mental states. These states are classified by their causal role within an agent, not their physical or chemical makeup. To understand a mental state, we must examine its consequences for the subject.
Consider this: Princess Leia believes Luke Skywalker is attractive. This belief, along with others (e.g., Luke is available, Luke might be interested), and desires, leads her to consider him a potential partner. However, this changes when she learns Luke is her brother. This new belief alters her behavior, demonstrating how mental states interact within a belief system to determine actions.
A core tenet of functionalism is that mental states are distinct from physical-chemical states. We can differentiate between a subject’s physical level (their physical states and processes) and a functional level (their mental states and processes and how they influence behavior).
Functionalism has two main types:
Psychological Functionalism
This type explains behavior through propositional attitudes like beliefs, desires, and intentions. Princess Leia’s beliefs are propositional attitudes, represented by sentences in a ‘language of thought’ and related by its internal logic.
Turing Machine Functionalism
This type equates a machine’s computational state with a person’s psychological state. Mental states are identified with computational states defined by their transactions. A mental state is not tied to a specific machine but to an operation achievable by various machines (William Bechtel, 1991). A program, as Andy Clark suggests, is a recipe for a job, defined abstractly. It’s a set of operations transforming inputs into outputs, a concept captured by a Turing machine.
In our example, Princess Leia’s mental states are like computer states, shifting to determine appropriate behavior. A key idea is that the same program (software) can run on different physical systems (hardware). The mind is to the brain as a program is to a machine. The human brain, for many functionalists, is a biological computer shaped by evolution and learning, processing information according to installed programs.