I think and there's a plenty of technical books, which are fun and/or philosophical at the same time. I still remember one of most poetic phrases I read was a comment to a proof in mathematical textbook.
It was in Polish and translation is something like that: "One probably has no soul, who - after reading this proof - can be totally free from a delicate thrill, which decent men used to feel after seeing something really beautiful."
It was in Polish and translation is something like that: "One probably has no soul, who - after reading this proof - can be totally free from a delicate thrill, which decent men used to feel after seeing something really beautiful."