James Robert Brown 
Philosophy of Mathematics [PDF ebook] 
An Introduction to a World of Proofs and Pictures

Philosophy of Mathematics is an excellent introductory text. This student friendly book discusses the great philosophers and the importance of mathematics to their thought. It includes the following topics:* the mathematical image* platonism* picture-proofs* applied mathematics* Hilbert and Godel* knots and nations* definitions* picture-proofs and Wittgenstein* computation, proof and conjecture.The book is ideal for courses on philosophy of mathematics and logic.