Paul Krugman lists...

...An Enquiry Concerning Human Understanding by the 18th-century British philosopher David Hume as one of five books he read in college that changed his life (my emphasis):

I was at that stage, a college sophomore or thereabouts, when you’re searching around, looking for belief systems. I think it’s actually a point when you’re quite vulnerable, because you are looking for someone who is going to offer you all the answers. Some people turn to religious orthodoxy, other people turn to Ayn Rand. One of my favourite lines – and I haven’t been able to find out who came up with it – is that “There’s an age when boys read one of two books. Either they read Ayn Rand or they read Tolkien’s Lord of the Rings. One of these books leaves you with no grasp on reality and a deeply warped sense of fantasy in place of real life. The other one is about hobbits and orcs.”

Then I read Hume’s Enquiry, this wonderful, humane book saying that nobody has all the answers. What we know is what we have evidence for. We do the best we can, but anybody who claims to be able to deduce or have revelation about The Truth – with both Ts capitalised – is wrong. It doesn’t work that way. The only reasonable way to approach life is with an attitude of humane scepticism. I felt that a great weight had been lifted from my shoulders when I read that book.