Full Idea
Animals not only have less reason than men, but they have none at all; for we see that very little of it is required in order to be able to speak.
Gist of Idea
Little reason is needed to speak, so animals have no reason at all
Source
René Descartes (A Discourse on Method [1637], §5.58)
Book Reference
Descartes,René: 'Discourse on Method/The Meditations', ed/tr. Sutcliffe,F.E. [Penguin 1968], p.75