David Sanford

Hume's arguments for the contention that causal necessity precludes logical necessity depend on the questionable principle that a cause must precede its effect. Hobbes' definition of entire cause, although it fails to account for causal priority, is not refuted by Hume. The objections of Myles Brand and Marshall Swain (Philosophical Studies, 1976) to my counterexample against Hume (Philosophical Studies, 1975) are ineffective. Their other objections to my criticisms of their argument against defining causation in terms of necessary and sufficient conditions (Synthese, 1970) are also mostly ineffective.

I criticize and emend J L Mackie's account of causal priority by replacing ‘fixity’ in its central clause by 'x is a causal condition of y, but y is not a causal condition of x'. This replacement works only if 'is a causal condition of' is not a symmetric relation. Even apart from our desire to account for causal priority, it is desirable to have an account of nonsymmetric conditionship. Truth, for example, is a condition of knowledge, but knowledge is not a condition of truth. My definitions of 'sufficient condition for' and 'necessary condition for' do not imply that p is a sufficient condition of q if and only if q is a necessary condition of p.