Full Idea
The incommensurability of the diagonal always exists, and so it is not in time.
Clarification
A diagonal cannot be expressed as a fraction of whole numbers (e.g. square root of 2)
Gist of Idea
The incommensurability of the diagonal always exists, and so it is not in time
Source
Aristotle (Physics [c.337 BCE], 221b36)
Book Reference
Aristotle: 'Physics', ed/tr. Waterfield,Robin [OUP 1996], p.112
A Reaction
This must make Aristotle sympathetic to Platonism in mathematics, even though he rejects the full theory of Forms. Such a view is not uncommon among modern philosophers. Presumably the incommensurability is true in all possible worlds? 'In'?