Mind, Matter, and Meaning

Putnam

Hilary Putnam (1926–2016) spent most of his career at Harvard and changed his mind more dramatically, more publicly, and more productively than almost any philosopher of the twentieth century. He started as a logical empiricist, became the most influential defender of functionalism, and then, in one of philosophy’s great self-reversals, published the arguments that demolished the functionalist program he had built. He championed semantic externalism, then qualified it. He eventually arrived at something close to direct realism about perception, which puts him, in his final philosophical incarnation, much closer to my thesis than to his own earlier positions. There is a lesson in the trajectory.

Major Works

  • “The Meaning of ‘Meaning’” (1975) — Twin Earth, semantic externalism, meanings are not in the head
  • Reason, Truth and History (1981) — internal realism and the rejection of metaphysical realism
  • Representation and Reality (1988) — against functionalism, from the inside
  • The Threefold Cord: Mind, Body, and World (1999) — natural realism, direct perception, rejection of the interface model
  • Words and Life (1994) — collected essays including philosophy of mind and language

Key Positions

Semantic externalism and Twin Earth. Putnam’s “The Meaning of ‘Meaning’” (1975) contains the most influential thought experiment of the second half of the twentieth century in philosophy of language. Twin Earth is exactly like Earth, except that the liquid in their lakes and rivers, which they call “water,” has the chemical composition XYZ rather than H₂O. When an Earthling and their Twin Earth counterpart both think “water is wet,” they are in identical internal states. But their words mean different things: the Earthling’s “water” refers to H₂O, the Twin Earthling’s to XYZ. As Putnam put it, meanings “just ain’t in the head.” Reference reaches out into the world, not inward into mental representations.

Multiple realization. Putnam’s original argument for functionalism: mental states can be realized in different physical substrates (carbon, silicon, who knows what). If mental states were identical to specific physical states, they couldn’t be multiply realized. Therefore mental states are functional kinds, not physical kinds. This argument later proved to be a double-edged sword: the same multiple realizability that supports functionalism against type identity theory also undermines functionalism against the full range of cases. A functional state realized so differently in different systems may not be the same mental state at all.

Against functionalism (the reversal). By Representation and Reality (1988), Putnam had turned against his own creation. His main objection: functionalism cannot account for the determinate content of mental states. Any sufficiently complex physical system can be interpreted as realizing any functional description; this makes functionalism trivially true and explanatorily hollow. The meaning and reference of mental states cannot be settled by functional role alone.

Natural realism and the later Putnam. The Threefold Cord (1999) is Putnam’s most important late work: a defense of “natural realism,” the view that perception puts us directly in contact with the world, not with representations or sense data that mediate between mind and world. The mind is not a box of inner representations; it is a relational, world-engaging capacity. This is not naïve realism in the sense of denying that perception can be mistaken; it is the rejection of the “interface” picture, the idea that experience always presents us with an inner screen rather than the world itself.

My View

Putnam stands as a fellow-traveler and a rival, depending on which turn of his career we follow. The book keeps his material anti-chauvinism, his externalism, and his rejection of the interface conception. It also takes seriously his demonstration that narrow functional and computational states classify contentful thought incorrectly in both directions. Meanings are not in the head, and internal role alone does not fix what a state concerns.

The externalist inheritance remains central. Reference reaches the world through environmental, causal-historical, and social relations rather than through a label attached to an inner concept. Kripke’s chains, Millikan’s producer-consumer history, and Burge’s anti-individualism develop different parts of that result. The book’s qualified reference theory therefore owes Putnam a substantial debt.

Two disagreements remain. Putnam considered a widened sociofunctionalism of organisms-cum-environments and ultimately rejected it because no finite equivalence rule could collect every realization of one belief. The book accepts the direction of the widening while declining the demand for finite algorithmic reduction: physically realized world-involving roles can remain objective and explanatory without forming a complete machine table. His natural realism also shares the anti-veil conclusion without supplying the house’s positive intentionalist account. Putnam clears the ground and identifies the required width; the identity claim and teleosemantics provide further structure.

See Semantic Externalism, Reference, and Functionalism.

  • Semantic Externalism — Putnam’s Twin Earth argument and its legacy
  • Functionalism — Putnam’s original functionalism and his reversal
  • Reference — the book’s qualified reference theory of meaning, which Putnam’s externalism underwrites
  • Intentionality — the world-directedness Putnam’s natural realism captures