Abstract

Broadly speaking, ancient concepts of causality in terms of explanatory priority have been contrasted with modern discussions of causality concerned with agents or events sufficient to produce effects. As Richard Taylor claimed in the 1967 Encyclopedia of Philosophy, of the four causes considered by Aristotle, all but the notion of efficient cause is now archaic. What we will consider here is a notion even less familiar than Aristotelian material, formal, and final causes—what we will call 'demonstrational causality'. Demonstrational causality refers to the dependence of the conclusion on the premises of a demonstration. Here, if ever, we have a case of explanational priority, since among other things what is required of the premises is that they be better known or more manifest than the conclusion. But, oddly enough, Aristotle and his medieval commentators describe demonstrational causality in the same terms as efficient causality. Aristotle speaks of the conclusion as an "effect" of the premises; his commentators speak of the "sufficiency" of first principles or axioms in producing the conclusion.