Functionalism

The position, attributed to Turing and von Neumann, that what a thing is is defined by what it does: a function is a relationship between inputs and outputs, independent of the mechanism that implements it, and therefore "multiply realizable" on any substrate that can compute. Agüera y Arcas extends it from minds (Putnam's philosophical functionalism, the Turing Test) to organs and organisms — the "Kidney Turing Test" — and to life itself, which becomes a composition of functions. It is the premise behind the claim that a next-token predictor is real rather than counterfeit intelligence. Its main in-corpus challenger is Tripaldi's substrate agency, which holds that substrates shape which functions are possible at all.