Full Idea
The stoics say there are eight parts of the soul: the five senses, the spermatic principle is us, the vocal part, and the reasoning part.
Gist of Idea
Eight parts of the soul: five senses, seeds, speech and reason
Source
report of Stoic school (fragments/reports [c.200 BCE]) by Diogenes Laertius - Lives of Eminent Philosophers 07.155
Book Reference
'The Stoics Reader', ed/tr. Inwood,B/Gerson,L.P. [Hackett 2008], p.57