Charles Wells, author (with Michael Barr) of Toposes, Triples, and Theories, now has a blog, gyre and gimble, devoted to how mathematicians use language.
He notes that the idea of completed infinity, which mathematicians take for granted, is still not well-liked outside of mathematics. The tone of the Wikipedia page on the subject (which consists mainly of quotes) tends towards the negative, for example.
At one of those bargain sales where the main library at UCLA occasionally disposes of “excess inventory,” I glanced through a very brief article on the subject of consciousness in an old encyclopedia of philosophy: “Indistinguishable from awareness. Nothing worthwhile has ever been written about it.”
This little jewel of deprecation came back to me when I was reading the quotes from medieval philosophy in the Wikipedia article about the actual infinite which Walt links in his post. Cantor’s recommendation of Augustine of Hippo was more promising (Struik, Concise History of Mathematics, p.81): “The transfinitum cannot be more energetically desired and cannot be more perfectly determined and defended than was done by St. Augustine.” But the relevant chapter of Civitas Dei (Book XII, Chapter 18) depends on Scriptural authority of dubious relevance (“The very hairs of your head are all numbered.”) and concludes with an encomium of God’s incomprehensible comprehension of incomprehensibles.
Scholastically-minded readers can find this chapter of Civitas Dei online at http://en.wikisource.org/wiki/The_City_of_God/Book_XII/Chapter_18