Hilary Putnam is one of the most important contemporary philosopher, who works in the analytic philosophy branch.
Metaphysics and ontology
During his career, Putnam has first defended a metaphysical realism that scientific statements have a truth value, before changing his design for an internal or pragmatic realism.
Philosophy of Mind
Putnam is probably best known for his contributions to the philosophy of mind. He was a pioneer and one of the most fervent advocates of functionalism or computationalism (roughly, this is the conception of the human spirit as analogues of a computer). However, it has revised its position in representation and reality, he explains why, in its revisited, functionalist design can not walk.
Philosophy of Language
One of the most important contributions of Hilary Putnam’s philosophy of language is the idea that the meaning is not right in the head (Just Is not Meaning in the head), an argument illustrated by the famous experiment thought the Earth twin.
In the field of epistemology, Putnam criticized in an article entitled “What theories are not” the dichotomy established by Carnap in “Testability and Meaning” (1956), between “observational statements” and “theoretical statements” and the hope of Carnap to build a formal language, accurate, without using imprecise terms. His criticism, which deals a serious blow to the project of logical positivism, is based on two main points:
the “observational statements” are not publicly observable things only, but also non-observable entities, conversely, there are theoretical terms which refer to observable things;
the interpretation of experience is not just about “observational statements”, but also on the “theoretical statements” “justification, science, carried out in all possible directions” observational statements are justified by theoretical statements and vice versa.
Putnam, however, is best-known thought experiment known as the “brains in a vat” (a modernised version of the Cartesian hypothesis of the evil genius). The argument is that no one can say consistently that it is a brain in a vat placed there by a mad scientist.
This is derived from the causal theory of reference. The words always refer to the kinds of things for which they were invented so that they make reference, ie the kinds of things their users, or their ancestors were able to experience. Therefore, if a person, Mary, for example, was a “brain in a vat”, each experiment was created by electrical impulses or other actions of a mad scientist, then the idea that Mary is a ” brain “does not refer to the” real “brain, when she and her linguistic community have never seen such a thing. Rather, she saw something that looked like a brain, but which was actually an image that has been transmitted the electrical impulse. Also, his idea of “tank” does not refer to a “real” tank. Therefore if, as a “brain in a vat”, she had to say “I am a brain in a vat”, she would in fact “I am a brain image in an image tank”, which is inconsistent. On the other hand, if it is not a “brain in a vat”, then say “I am a brain in a vat” is still inconsistent. It is a form of epistemological externalism: knowledge or justification depends on factors outside of the mind and is determined not only internally.
Putnam has since said that his real target with this argument was never scepticism but the metaphysical realism. Once a realism of this kind assumes the existence of a gap between how the man views the world and the way the world really is, sceptical scenarios such as this one or that the Evil Genius Descartes presented a formidable challenge. Putnam, showing that such a scenario is impossible, attempts to show that this concept of the design gap between the human world and the world as it is in itself absurd. The man can not have a point of view of Sirius on reality. It is limited to its conceptual schemes. Metaphysical realism is false, according to Putnam.
The collapse of the fact/value dichotomy (2002)
In The Collapse of the Fact / Value Dichotomy (2002), Putnam addresses the dichotomy is equivalent, founder of the project of the Vienna Circle and a strong presence in Language, Truth and Logic (1936) Alfred Ayer, without provided rather subscribe to the relativistic theories supported by Richard Rorty in Objectivism, Relativism and Truth (1994). If Putnam criticises the emotivism of Ayer on the one hand, and intuitionism of GE Moore on the other hand, he maintains, however, the distinction does value
First, he argues that one can not distinguish between facts and concepts of axiological concepts, but only between descriptive and prescriptive functions of concepts. It relies on ‘thick ethical concepts “(thick Ethical concepts) that combine descriptive function and prescriptive12. Cruelty illustrates these concepts can not be classified either among the judgments made exclusive nor among the exclusive value judgments. It is a thick ethical concept that has simultaneously descriptive and prescriptive functions. About these concepts, Putnam rejects the solution of RM Hare, to decide between descriptive and prescriptive content. He finally takes a position inspired by pragmatist John Dewey, in order to obtain a relative objectivity in ethics.