The abortion debate rages on. Yet the two most popular positions seem to be clearly mistaken. Conservatives maintain that a human life begins at conception and that therefore abortion must be wrong because it is murder. But not all killings of humans are murders. Most notably, self defense may justify even the killing of an innocent person.Liberals, on the other hand, are just as mistaken in their argument that since a fetus does not become a person until birth, a woman (...) may do whatever she pleases in and to her own body. First, you cannot do as you please with your own body if it affects other people adversely. Second, if a fetus is not a person, that does not imply that you can do to it anything you wish. Animals, for example, are not persons, yet to kill or torture them for no reason at all is wrong. (shrink)

A solution to the sorites paradox is obtained by distinguishing three formats of the sorites argument and appraising them in the light of four fundamental considerations: (i) the appropriate notion of truth for the application of vague predicates to their borderline cases, (ii) a certain construal of borderline cases, (iii) a certain freedom of use of vague terms not enjoyed by non-Vague terms and (iv) the revocation of that freedom by deductive contexts.

To accommodate vague statements and predicates, I propose an infinite-valued, non-truth-functional interpretation of logic on which the tautologies are exactly the tautologies of classical two-valued logic. iI introduce a determinacy operator, analogous to the necessity operator in alethic modal logic, to allow the definition of first-order and higher-order borderline cases. On the interpretation proposed for determinacy, every statement corresponding to a theorem of modal system T is a logical truth, and I conjecture that every logical truth on the interpretation corresponds (...) to a theorem of T. the interpretation is extended to predicate logic. A borderline case of a predicate 'F’ is neither determinately F nor determinately not-F. Traditional sorites arguments are seen to fall apart early in their gradual stepwise passage from truth to falsity. (shrink)