Full Idea
The ingredient of necessity [in Aristotle's account of consequence] is required by his demand that proof should produce 'understanding' [episteme], coupled with his claim that understanding something involves seeing that it cannot be otherwise.
Gist of Idea
Aristotle's proofs give understanding, so it can't be otherwise, so consequence is necessary
Source
report of Timothy Smiley (Conceptions of Consequence [1998], p.599) by Ian Rumfitt - The Boundary Stones of Thought 3.2
Book Reference
Rumfitt,Ian: 'The Boundary Stones of Thought' [OUP 2015], p.70
A Reaction
An intriguing reverse of the normal order. Not 'necessity in logic delivers understanding', but 'reaching understanding shows the logic was necessary'.