Philosopher

Hilary Putnam

Philosophy of Mind

Hilary Putnam, born Hilary Whitehall Putnam in 1926 and died in 2016, was an American philosopher who worked across philosophy of mind, philosophy of language, philosophy of mathematics and epistemology and was known for repeatedly revising his own earlier positions over a long career at Harvard. In philosophy of mind he developed functionalism and the argument for multiple realizability, the idea that a mental state can be realized by many different physical substrates rather than identified with any one type of brain state, and in philosophy of language he introduced the Twin Earth thought experiment to argue for semantic externalism, the view that the meaning of a word depends partly on facts outside the speaker's own head. With Willard Van Orman Quine he formulated the Quine-Putnam indispensability argument for the reality of mathematical objects, and with Martin Davis he contributed to the Davis-Putnam algorithm used in automated theorem proving, work that has had a lasting influence in computer science as well as philosophy.

Facts

Birth Year

1926 1

Defining Moment

Introduced the Twin Earth thought experiment in The Meaning of Meaning (1975), establishing semantic externalism and the view that meaning is not entirely determined within the head. 1

Birth Date

1926-07-31 1

Notable Publication

Reason, Truth, and History (1981) 1

Office Held

Cogan University Professor, Harvard University, retired 2000 as Cogan University Professor Emeritus; earlier taught at Northwestern University, Princeton University and MIT 1

Death Year

2016 1

Death Date

2016-03-13 1

Birthplace

Chicago, Illinois, United States 1

Death Place

Arlington, Massachusetts, United States 1

Tradition

Analytic philosophy 1

Classification

Nationality

United States 1

Tradition

Tradition (category)

Analytic 1

FAQs

What is the Twin Earth thought experiment?

A scenario with an identical planet whose water is XYZ rather than H2O, used to argue that meaning is not just in the head.

Twin Earth is Hilary Putnam's thought experiment for showing that meaning is not determined only by what is in a speaker's head. On Twin Earth everything is identical to Earth, except that its lakes, rivers and oceans are filled with XYZ rather than H2O. When an earthling and his physically identical twin on Twin Earth each say the word water, the two words have different meanings, even though the speakers are physically indistinguishable. Putnam concluded that meaning cannot be determined solely by what is in the speakers' heads, which led him to semantic externalism. He laid out his views on meaning in Meaning and Reference (1973) and then in The Meaning of Meaning (1975).

Connections

Associated With

Functionalism

Putnam's 1967 paper set out the machine-state version and its multiple-realizability argument, though he later grew critical of functionalism himself.

Source Functionalism (Stanford Encyclopedia of Philosophy)

Philosophy of Artificial Intelligence

Putnam's functionalism and computational theory of mind gave the philosophical framing, mental states as functional/computational states, that much of the field still argues from or against.

The Brain in a Vat Argument

Putnam gave the scenario its contemporary form and its semantic-externalist reply in Reason, Truth and History (1981).

Source Brain in a Vat Argument (Internet Encyclopedia of Philosophy)

Twin Earth Thought Experiment