Off the top of my head I can't think of any I'd recommend. What I learned from trying to study philosophy is that the place to look is in other fields. I.e. if you understand math or history or aeronautical engineering very well, the most abstract of the things you know are what philosophy is supposed to be teaching. Books on philosophy per se are either highly technical stuff that doesn't matter much, or vague concatenations of abstractions their own authors didn't fully understand (e.g. Hegel).
It can be interesting to study ancient philosophy, but more as a kind of accident report than to teach you anything useful.
BTW, while this was an interesting question, it's not really about startups, so I'm killing it.
Way beyond interesting. Thanks for responding to his off-topic question. I wanted to ask the same one, but managed restraint. "Ask Paul" would be an awesome section and probably serve as a great FAQ. I suppose it'd be annoying for you though.
I think it's about time for you to let the community go off-topic. I understand the motive for keeping this site focused on start-ups but allowing another area of the site for general link-sharing and discussion will be enlightening for all of us.
I would advocate adding the ability to ignore users who join after a specified date. This would allow everyone to freeze the community just the way they like it. I think it would be an elegent hack in lieu of competent recommendation.
I think the trick to preserve the "old reddit" on a new site would be to allow people to choose whose stuff they get to see, i.e. filter by users. That way the early elite doesn't have to get washed out.
It can be interesting to study ancient philosophy, but more as a kind of accident report than to teach you anything useful.
BTW, while this was an interesting question, it's not really about startups, so I'm killing it.