efficient cause

In Aristotle's philosophy, one of the four causes of things. The efficient cause of a man, according to Aristotle, is his father. The other three causes of a man are material cause (flesh), formal cause (the form of man), and final cause (the end, or purpose, of human life).

Only two of Aristotle's causes answer to English usage: the efficient and the final causes. The Greek word translated as ‘cause’ means something more like ‘responsible factor’ or ‘necessary condition’.