Full Idea
Reasoning is based on certain statements made in such a way as necessarily to cause the assertion of things other than those statements and as a result of those statements.
Gist of Idea
Reasoning is a way of making statements which makes them lead on to other statements
Source
Aristotle (Sophistical Refutations [c.331 BCE], 165a01)
Book Reference
Aristotle: 'Sophistical Refutations, On the Cosmos etc (III)', ed/tr. Forster,E.S. /Furley,D.J. [Harvard Loeb 1955], p.13