Full Idea
In assigning the essence [ti estin], it is more appropriate to state the genus than the differentiae; for he who describes 'man' as an 'animal' indicates his essence better than he who describes him as 'pedestrian'.
Gist of Idea
Genus gives the essence better than the differentiae do
Source
Aristotle (Topics [c.331 BCE], 128a24)
Book Reference
Aristotle: 'Posterior Analytics and Topica', ed/tr. Tredennick,H/Forster,ES [Harvard 1960], p.477
A Reaction
See Idea 12279. This idea is only part of the story. My reading of this is simply that assigning a genus gives more information. We learn more about him when we say he is a man than when we say he is Socrates.
Related Idea
Idea 12279 The differentia indicate the qualities, but not the essence [Aristotle]