Full Idea
Cantor taught us to regard the totality of natural numbers, which was formerly thought to be infinite, as really finite after all.
Gist of Idea
Cantor presented the totality of natural numbers as finite, not infinite
Source
report of George Cantor (works [1880]) by John Mayberry - What Required for Foundation for Maths? p.414-2
Book Reference
'Philosophy of Mathematics: anthology', ed/tr. Jacquette,Dale [Blackwell 2002], p.414
A Reaction
I presume this is because they are (by definition) countable.
Related Idea
Idea 17797 Cantor extended the finite (rather than 'taming the infinite') [Mayberry]