In all of this Fârâbî is broadly following the Aristotelian idea that, for any composite object X, we can ask “what is X?” and answer the question either by giving a definition of X spelling X out into many in-some-sense-constituents of X, or by giving some one such constituent of X, which is a partial answer to “what is X?”.[28] Fârâbî is also following Aristotle in insisting that all of the things which should be mentioned in the definition of X are causes of X’s being (“the thing by which [