Full Idea
Those who say there are Forms abstract natural properties, even though they are less separable than mathematical properties. This is clear if you try to define both the objects themselves and their attributes.
Gist of Idea
You can't abstract natural properties to make Forms - objects and attributes are defined together
Source
Aristotle (Physics [c.337 BCE], 193b36)
Book Reference
Aristotle: 'Physics', ed/tr. Waterfield,Robin [OUP 1996], p.36
A Reaction
(Compare Idea 9788) This is Frege's black and white cats, where you cannot abstract the black without thinking of the cat, but Aristotle thinks mathematical abstraction is more feasible.
Related Idea
Idea 9788 Mathematicians study what is conceptually separable, and doesn't lead to error [Aristotle]