I had to look up a Russell quote the other day, and that’s when I noticed that many of his books — including the Foundations of Geometry, Our Knowledge of the External World, Introduction to Mathematical Philosophy, Analysis of Mind, Principles of Mathematics, Mysticism and Logic, and Principia Mathematica (annoyingly, only vol. II) — are available in their full glory through Google Books. There are lots of other gems, including Hilbert’s Grundlagen der Geometrie, the Tractatus, etc. But beware: the Google metadata are unreliable, to say the least (see Geoff Nunberg on Google Books: A Metadata Trainwreck).
Hi Richard, Now that you mentioned Hilbert, do you know of any English editions of his works, or at least reliable English translations, even if not published? (I may have asked this before). I am wondering about papers, mostly; the Grundlagen is available in many languages, as is his book on algebraic number theory.