Validity (Q2776068)

Priest argues that validity -- deductive and inductive, including both probabilistic and nonmonotonic reasoning -- is to be understood as truth-preservation in all structures of a certain kind, deductive validity being the limiting case of truth-preservation in all structures whatsoever. Structures may, but need not, have such properties as consistency or completeness. Logic is then the study of validity in this sense; its normativeness is hypothetical, being how one ought to reason if one wishes to reason in such a way as to preserve the transmission of truth (from premisses to conclusion) and the retransmission of lack of truth (from conclusion to the adjunction of the premisses).NEWLINENEWLINEFor the entire collection see [Zbl 0972.00009].