Full Idea
In definitions the first term to be assigned ought to be the genus.
Gist of Idea
In definitions the first term to be assigned ought to be the genus
Source
Aristotle (Topics [c.331 BCE], 132a12)
Book Reference
Aristotle: 'Posterior Analytics and Topica', ed/tr. Tredennick,H/Forster,ES [Harvard 1960], p.507
A Reaction
We mustn't be deluded into thinking that nothing else is required. I take the increasing refinement of differentiae to be where the real action is. The genus gives you 70% of the explanation.