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Philosophy of Mind (late 1960s)
Putnam diagram of multiple realizability shown in photo where M stands for mental and P stands for physical. It can be seen that more than one P can instantiate one M, but not vice versa. Causal relations between states are represented by the arrows (M1 goes to M2, etc.). Putnam's best-known work concerns philosophy of mind. His most noted original contributions to that field came in several key papers published in the late 1960s. -
Work at Princeton University (1961)
At Princeton worked on mathematical logic. He worked on one of the 23 unsolved problems in mathematics identified by David Hilbert. He also found a general algorithm for solving Diophantine equations. Putnam thesis called the Quine-Putnam indispensability thesis is an argument for the reality of mathematical entities, later espousing the view that mathematics is not purely logical, but “quasi-empirical”. -
Philosophy of Logic (1971)
Philosophy of Logic was an essay about the ontological problem in the philosophy of logic and mathematics. The issue of whether the abstract entries spoken of in logic and mathematics really exist. It also covers the question of whether or not reference to these abstract entities are really indispensable in logic and whether it is necessary in physical science in general. -
Philosophy of Language (1973)
One of Putnam's contributions to philosophy of language is his claim that "meaning just ain't in the head". His views on meaning, in Meaning and Reference 1973, and The Meaning of 'Meaning' 1975, use his famous "Twin Earth" thought experiment to illustrate that the meaning of terms are determined by factors outside the mind.According to Putnam, on Twin Earth everything is identical to Earth, except that its lakes, rivers and oceans are filled with XYZ whereas those of earth are filled with H2O.
