Full Idea
There seem to be two producers of movement, either desire or practical intellect, but practical reason begins in desire.
Gist of Idea
Practical reason is based on desire, so desire must be the ultimate producer of movement
Source
Aristotle (De Anima [c.329 BCE], 433a16)
Book Reference
Aristotle: 'De Anima (On the Soul)', ed/tr. Lawson-Tancred,H.C. [Penguin 1986], p.214