Full Idea
Nothing is actually infinite. A thing is infinite only potentially.
Gist of Idea
Infinity is only potential, never actual
Source
Aristotle (Coming-to-be and Passing-away (Gen/Corr) [c.335 BCE], 318a21)
Book Reference
Aristotle: 'The Basic Works of Aristotle', ed/tr. McKeon,Richard [Modern Library Classics 2001], p.480
A Reaction
Aristotle is the famous spokesman for this view, though it reappeared somewhat in early twentieth century discussions (e.g. Hilbert). I sympathise with this unfashionable view. Multiple infinites are good fun, but no one knows what they really are.