Their judgment was based more upon blind wishing than upon any sound prevision; for it is a habit of mankind to entrust to careless hope what they long for, and to use sovereign reason to thrust aside what they do not fancy.
-- Thucydides, Greek Historian, ca. 5th century BCE (Book IV, 108)
I like Thucydides for the way he tries to explain history in terms of real-politik, people, their drives and especially without including the gods in an explanation, somewhat similar to Hippocrates.
Interestingly, a modern version of this appeared in Neal Stephenson's Anathem:
Never believe a thing simply because you want it to be true
where it's called Diax's Rake.
Anathem is a great book, I'd like to add, and quite well aligned with many of the LW themes.
I have to disagree on two counts. First, Diax's Rake is explicitly a reference to Thucydides, (or, more spoilerifically, Thucydides' "referenced" Diax for some value of reference), so it's not really interesting that it appeared in Anathem.
Secondly, Anathem isn't actually aligned with LW themes at all. It might appear that way at the beginning, but Stephenson undoes all of it with the spoiler twist at the end.
This is our monthly thread for collecting these little gems and pearls of wisdom, rationality-related quotes you've seen recently, or had stored in your quotesfile for ages, and which might be handy to link to in one of our discussions.