Full Idea
What we might call 'Cantor's Thesis' is that there won't be a potential infinity of any sort unless there is an actual infinity of some sort.
Gist of Idea
Cantor proposes that there won't be a potential infinity if there is no actual infinity
Source
report of George Cantor (works [1880]) by William D. Hart - The Evolution of Logic 1
Book Reference
Hart,W.D.: 'The Evolution of Logic' [CUP 2010], p.29
A Reaction
This idea is nicely calculated to stop Aristotle in his tracks.