Full Idea
The object of scientific knowledge is what is necessary.
Clarification
'Necessary' things have to be the way they are. 'Knowledge' here is the Greek word 'epistemé'
Gist of Idea
The object of scientific knowledge is what is necessary
Source
Aristotle (Nicomachean Ethics [c.334 BCE], 1139b24)
Book Reference
Aristotle: 'Ethics (Nicomachean)', ed/tr. ThomsonJ A K/TredennickH [Penguin 1976], p.207
A Reaction
This is diametrically opposed to the Humean view, which takes the nature of each thing, and the laws which guide it, to be contingent. Kripke has pointed us towards necessities in nature.