Mere reasoning, however, can never set anything going, but only reasoning about means to an end⁠—what may be called practical reasoning (which practical reasoning also regulates production; for in making anything you always have an ulterior object in view⁠—what you make is desired not as an end in itself, but only as a means to, or a condition of, something else; but what you do is an end in itself, for well-doing or right action is the end, and this is the object of desire).

Purpose, then, may be called either a reason that desires, or a desire that reasons; and this faculty of originating action constitutes a man.

No past event can be purposed; e.g. no one purposes to have sacked Troy; for no one deliberates about that which is past, but about that which is to come, and which is variable: but the past cannot be undone; so that Agathon is right when he says⁠—