Tractatus Logico-Philosophicus
His first book – "The Pyrgic Puzzler" – a collection of 80 puzzles with illustrations by Michael Harrington, was written without any particular view to publication, but was taken up by Iris Murdoch who wrote an introduction for it in which she said that although she's not a great solver of puzzles, the book may be 'read as literature' just as in the case of Wittgenstein's "Tractatus Logico-Philosophicus" and the Bible.