Article abstract: Putnam is probably best known for his development and defense of Turing machine functionalism, for his concept of semantic externalism and the Twin Earth thought exercise, and for internal realism.
On July 31, 1926, Hilary W. Putnam was born in Chicago to Samuel and Riva Putnam. Samuel was a writer and a journalist and a member of the Communist Party during the Depression. Putnam’s parents lived in France until 1934 and then in Philadelphia, where Putnam was graduated from the University of Pennsylvania in 1948. He studied at Harvard for a year before eventually earning his Ph.D. from the University of California, Los Angeles, in 1951.
At the age of twenty-two, Putnam married Erna Diesendruck on November 1, 1948. They divorced in 1962, and he married Ruth Anna Hall on August 11 of that year. He became the father of four children, two daughters and two sons.
Putnam began teaching philosophy as an instructor at Northwestern University in 1952. That year was followed by a stint at Princeton, where he advanced to assistant and later associate professor. He then taught, as a full professor, at the Massachusetts Institute of Technology from 1961 to 1965. Beginning in 1965, he taught philosophy at Harvard under various titles, including Walter Beverly Pearson Professor of Modern Mathematics and Mathematical Logic and Cogan University Professor. He served the Eastern Division of the American Philosophical Association as vice president for 1975-1976 and as president for 1976-1977.
According to an article that appeared in the news magazine U.S. News and World Report, Putnam supported the draft resistance during the Vietnam War and later, having become more radicalized, assumed the position of Harvard faculty sponsor of Students for a Democratic Society (SDS) and joined a Maoist group, the Progressive Labor Party. According to Putnam, this Marxist period in his life may have been a retracing of his father’s footsteps.
Putnam’s topics include a vast array of philosophical issues, from the theoretical foundations of quantum physics to the epistemology of ethics, but as indicated by the title of his Ph.D. dissertation, The Meaning of the Concept of Probability in Application to Finite Sequences, his early work focused primarily on logic and the philosophy of mathematics. A notable contribution in these fields is his work with Martin Davies and Julia Robinson. Davies and Putnam teamed to write “Reductions of Hilbert’s Tenth Problem,” and Putnam, Davies, and Robinson wrote “The Decision Problem for Exponential Diophantine Equations.”
In the late 1950’s, Putnam proposed a program in the philosophy of mind that is now widely known as functionalism. Functionalism, according to Putnam, is the view that mental states, rather than being identified as some physical state, are defined by their inputs and outputs, or causes and effects. Putnam stated that the mind may be viewed as a “probabilistic automaton” of which, in some state, the transition to other states and the display of certain behaviors can be probabilistically predicted based on a given input, or set of inputs. The Turing machine, often used by Putnam to explain and defend functionalism, is a special type of probabilistic automaton with transition probabilities 1,0. That is, the strictly binary probabilities of the Turing machine are, more than probabilistic, deterministic.
Putnam’s argument rests largely on the thesis that states such as pain are not physical-chemical states of the brain, but functional states of the entire organism. Given some typical state of the organism, pain is the state caused by a certain input, such as a pinch or a pinprick, that in turn causes other states, such as worry or apprehension, and behaviors (output) such as exclaiming, “Ouch!” What he intended to show, through functionalism, was that organisms composed of physically possible but different material could as easily exhibit mentality as do humans. From this we learn that what we really want to know about the mind is its functional organization, not the nature of its either mysterious or strictly physical substance.
About the time that Putnam became more politically radical, his philosophical views moved away from positivism and became less concerned with logic and the philosophy of mathematics. The focus of his work shifted to human experience and how human experience is affected by fields such as logic, philosophy of mathematics, epistemology, and other areas of philosophy.
Putnam often changed his mind. Early in his career, he was a strong proponent of the positivist movement, which he later abandoned and even criticized. In addition, although he defended and developed the theory of functionalism, he came to argue that functionalism fails because the intentional cannot be reduced to the computational or physical....
(The entire section is 2041 words.)