The computer revolution transformed debates about whether machines can think, proposing the computational theory of mind (CTM)—the view that the mind is a computational system. Computationalists argue that mental processes like reasoning and perception are computations. CTM dominated cognitive science in the 1960s–1970s but now faces rival paradigms. Key tasks include defining what it means for the mind to “compute” and relating computational description to neurophysiological and intentional accounts.

Alan Turing’s 1936 paper introduced the Turing machine, an abstract model with unlimited memory that manipulates symbols via a finite set of mechanical instructions. Turing argued any humanly executable symbolic algorithm can be replicated by a Turing machine, establishing the digital paradigm of discrete symbolic configurations. He also proved the existence of a universal Turing machine that can mimic any other Turing machine, laying the foundation for general-purpose computers.

Rapid progress in computer science spurred artificial intelligence (AI) research aiming to build “thinking machinery.” Early success came with the Logic Theorist program (Newell and Simon, 1956), which proved 38 theorems from *Principia Mathematica* and even found a simpler proof. Initial optimism predicted thinking machines within years, but overconfidence later led to skepticism.