Full Idea
There is a conflict between the syllogistic theory of demonstration of the Posterior Analytics, with its austere programme of certainties, and how Aristotle actually does science.
Gist of Idea
Aristotle doesn't actually apply his theory of demonstration to his practical science
Source
comment on Aristotle (Posterior Analytics [c.327 BCE]) by Armand Marie LeRoi - The Lagoon: how Aristotle invented science 104
Book Reference
Leroi,Armand Marie: 'The Lagoon: how Aristotle invented science' [Bloomsbury 2014], p.348
A Reaction
Leroi observes that there are no demonstrations anywhere in the biological writings. Biology probably lends itself least to such an approach.