# Hilary Putnam ![[50 Resources/51 Attachments/51.03 Public/2026-05-04 Hilary Putnam.jpg|400]] Hilary Putnam (1926–2016) was an American philosopher at Harvard who made foundational contributions to [[Philosophy of Mind]], philosophy of language, and philosophy of science. He co-founded [[Functionalism]] with [[Jerry Fodor]], arguing that mental states are defined by their functional roles rather than their physical substrate—the same way software can run on different hardware. Putnam later critiqued his own functionalism and developed semantic externalism: the meaning of words depends partly on the external world ("meanings ain't in the head"). His "Twin Earth" thought experiment showed that two internally identical people could mean different things by "water" depending on their environment. ## Key Contributions | Concept | Description | |---------|-------------| | **Functionalism** | Mental states defined by causal roles | | **Twin Earth** | Meaning depends on external world | | **Multiple realizability** | Same mental state, different physical bases | ## Quotes <!-- QueryToSerialize: LIST FROM #type/quote AND [[Hilary Putnam]] WHERE public_note = true SORT file.name ASC --> ## Books <!-- QueryToSerialize: LIST FROM #type/book AND [[Hilary Putnam]] WHERE public_note = true SORT file.name ASC --> ## References - Putnam, H. (1967). "The Nature of Mental States" - https://en.wikipedia.org/wiki/Hilary_Putnam ## Related - [[Philosophy of Mind]] - [[Functionalism]] - [[Jerry Fodor]] - [[Consciousness]]