When the time comes, there is no moment for reasoning. And if you have not done your inquiring beforehand, there is most often shame. Reading books and listening to people's talk are for the purpose of prior resolution.
Yamamoto Tsunetomo, Hagakure: The Book of the Samurai
A monthly thread for posting any interesting rationality-related quotes you've seen recently on the Internet, or had stored in your quotesfile for ages.