Functionalism Functionalism is a theory about the nature of mental states. According to functionalism, mental states are identified by what they do rather than by what they are made of. This can be understood by thinking about artifacts like mousetraps and keys. En particulier, the original motivation for functionalism comes from the helpful comparison of minds with computers. But that is only an analogy. Le

Epistemic Circularity An epistemically circular argument defends the reliability of a source of belief by relying on premises that are themselves based on the source. It is a widely shared intuition that there is something wrong with epistemically circular arguments. William Alston, who first used the term in this sense, argues plausibly that there is no way to know or to be justified in believing

Natural Deduction Natural Deduction (ND) is a common name for the class of proof systems composed of simple and self-evident inference rules based upon methods of proof and traditional ways of reasoning that have been applied since antiquity in deductive practice. The first formal ND systems were independently constructed in the 1930s by G. Gentzen and S. Jaśkowski and proposed as an alternative to Hilbert-style axiomatic systems. Gentzen introduced a

Modal Metaphysics Modal metaphysics concerns the metaphysical underpinning of our modal statements. These are statements about what is possible or what is necessarily so. We can construe the primary question of modal metaphysics as, “When we make a statement about what is possible or necessary, what determines the truth or falsity of the statement?” As an illustration, consider the statement “It is possible for me

Héraclite (fl. c. 500 avant notre ère) A Greek philosopher of the late 6th century BCE, Heraclitus criticizes his predecessors and contemporaries for their failure to see the unity in experience. He claims to announce an everlasting Word (Logos) according to which all things are one, dans un certain sens. Opposites are necessary for life, but they are unified in a system of balanced exchanges. The world itself