Aristotle maintained that four separate causes are necessary before anything exists: the material cause, the formal, the final, and the moving cause. The first is the antecedents from which the thing comes into existence; the second, that which gives it its individuality; the moving or efficient cause is that which causes matter to assume its individual forms; and the final cause is that for which the thing exists. According to Aristotle, matter is eternal.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894
More on Aristotelian Philosophy from Fact Monster: