And then this came across my Twitter feed (@Nebusj, for the record):
It is to Project Gutenberg’s edition of David Hilbert’s The Foundations Of Geometry. David Hilbert you may know as the guy who gave us 20th Century mathematics. He had help. But he worked hard on the axiomatizing of mathematics, getting rid of intuition and relying on nothing but logical deduction for all mathematical results. “Didn’t we do that already, like, with the Ancient Greeks and all?” you may ask. We aimed for that since the Ancient Greeks, yes, but it’s really hard to do. The Foundations Of Geometry is an example of Hilbert’s work of looking very critically at all of the things we assume, and all of the things that we need, and all of the things we need defined, and trying to get at it all.
Hilbert gave much of 20th Century Mathematics its shape with a list presented at the 1900 International Congress of Mathematicians in Paris. This formed a great list of important unsolved problems. Some of them have been solved since. Some are still unsolved. Some have been proven unsolvable. Each of these results is very interesting. This tells you something about how great his questions were; only a great question is interesting however it turns out.
The Project Gutenberg edition of The Foundations Of Geometry is, mercifully, not a stitched-together PDF version of an ancient library copy. It’s a PDF compiled by, if I’m reading the credits correctly, Joshua Hutchinson, Roger Frank, and David Starner. The text was copied into LaTeX, an incredibly powerful and standard mathematics-writing tool, and compiled into something that … looks a little bit like every mathematics paper and thesis you’ll read these days. It’s a bit odd for a 120-year-old text to look quite like that. But it does mean the formatting looks familiar, if you’re the sort of person who reads mathematics regularly.
(There are a couple lines that read weird to me, but I can’t judge whether that owes to a typo in the preparation of the document or just that the translation from Hilbert’s original German to English produced odd effects. I’m thinking here of Axiom I, 2, shown on page 2, which I understand but feel weird about. Roll with it.)