This book began by stressing the role of infinity in mathematics, its presence in the concept of number, and the importance of learning to live with it. Since then, infinity has appeared in many situations, and we have seen many ways to approach and tame it. Still, it is remarkable how often we succeed. Even if the world of ideas is infinite, as Dedekind believed, there is no doubt that proofs
... [Show full abstract] are finite, so success with infinity depends on capturing its properties by finite methods. Induction is one such method, but there are others.