the.com/functionalism

means A theory that mental states (beliefs, desires, pain, etc.) are defined by their causal roles — what triggers them and what they lead to — not by the physical stuff that realizes them, which means a brain, a silicon chip, or in principle anything else could all 'have a mind' if wired the right way.

from The word traces to Latin functio, 'a performing,' from fungi, 'to perform or discharge.' In philosophy of mind, functionalism rose in the mid-20th century partly as a reaction against identity theory (the idea that mental states just ARE specific brain states) — philosophers like Hilary Putnam argued that what makes something pain isn't its physical makeup but its functional role, the job it does between input and output. The name itself borrows the same 'form follows function' logic that shows up in functionalist architecture and functionalist sociology — separate traditions, but all leaning on that same Latin root: it's not what you're built from, it's what you're built to do.