TITLE: Books on the history of foundations of mathematics?
QUESTION [6 upvotes]: Can you point me to some books on the history of the foundations of mathematics? At the moment I'm searching for something light because of my lack of mathematical maturity and also the fact that I'm self-learning this, my intention is to make a two-step program: First a light book about it then one a little more serious on the topic.

REPLY [2 votes]: I liked From Frege to Gödel: A Source Book in Mathematical Logic, 1879–1931, edited by Jean van Heijenoort. It contains many of the original crucial papers, such as the Frege axioms that turned out to be inconsistent, the letter that Russell sent him pointing this out, and the sad epilogue he wrote to his book afterward; Gödel's original incompleteness paper, and a lot of crucial developments in between.
I am a big fan of reading original materials when possible. They are often groundbreaking not just because of their results but because of the presentation. It's often interesting to compare the actual original ideas with what people now say the original ideas were; these often don't match at all.  Original materials give a better sense of the historical development of ideas, which often brings its own insight into why things are done the way they are.  Famous mathematicians become famous in part because of the brilliance of their thought and clarity of their expression of it, and so the original exposition is often brilliant and clear where an exposition by some later, lesser person is not.  On the other hand, sometimes the  original exposition is confusing, because the ideas we not completely clear yet.  But if you are trying to understand the history, there is no substitute for the original documents.