Full Idea
Epicurus says the soul is a blend of fiery stuff (for bodily warmth), airy stuff (rest), breath (motion), and a nameless stuff (sense-perception).
Gist of Idea
Soul is made of four stuffs, giving warmth, rest, motion and perception
Source
report of Epicurus (fragments/reports [c.289 BCE]) by Aetius - fragments/reports 4.3.11
Book Reference
'Hellenistic Philosophy: Intro Readings', ed/tr. Inwood,B. /Gerson,L. [Hackett 1988], p.62
A Reaction
Obviously Epicurus thought the four stuffs were different combinations of atoms, rather than being elements. Is there no stuff which gives reason? Reason must reduce to motion, presumably.