The Two Ideas of the "Oyster", p 438
[The idea of Gödel numbering] is an idea which goes far beyond the confines of mathematical logic, whereas the Cantor trick, rich though it is in mathematical consequences, has little if any relation to issues in real life.
Supernatural Numbers, p 454
[R]ecall that there is another number whose square is also minus one: -i. Now i and -i are not the same number. They just have a property in common. The only trouble is that it is the property which defines them! We have to choose one of them --it doesn't matter which one-- and call it "i". In fact there's no way to tell them apart. So for all we know we could have been calling the wrong one "i" for all these centuries and it would have made no difference.
[Supernaturals Are Useful] ...But Are They Real? p 456
By taking the step of formalization, we were committing ourselves to accepting whatever passive meanings these terms might take on.
Bifurcations in Number Theory, and Bankers, p 457
Mathematics only tells you answers to questions in the real world after you have taken the one vital step of choosing which kind of mathematics to apply.