Abstract
There is what might be called a ‘majority position’ in the history of Western philosophy according to which causes are sufficient for or ‘necessitate’ their effects. However, there is also a singificant ‘minority position’ according to which causes are necessary relative to their effects. The second/third century A.D. Peripatetic Alexander of Aphrodisias is an ancient representative of the minority position. He attributes his own view — with some justification, I shall suggest – to Aristotle. This paper has two, somewhat loosely connected purposes. The first is to explore the origin of the conception of ‘causes’ as necessary conditions in Aristotle, particularly in On Generation and Corruption 2.11 and Posterior Analytics 2.12, and the development and use of the conception in Alexander's De fato. The second purpose of the paper is to explore and criticize a sophisticated contemporary version of the conception of causes as ‘necessary in the circumstances,’ that of J.L. Mackie.