Full Idea
The region beyond the heavens seems to be infinite because it does not give out in our thoughts.
Gist of Idea
The heavens seem to be infinite, because we cannot imagine their end
Source
Aristotle (Physics [c.337 BCE], 203b25)
Book Reference
Aristotle: 'Physics', ed/tr. Waterfield,Robin [OUP 1996], p.65
A Reaction
An interesting case of inconceivability (of a limit) implying impossibility. But it is undeniable that the outer limit of the cosmos is unimaginable for us. Is there a 'Road Closed' sign?