The surest way to corrupt a youth is to instruct him to hold in higher esteem those who think alike than those who think differently.
There are various eyes. Even the Sphinx has eyes: and as a result there are various truths, and as a result there is no truth.
Those who cannot understand how to put their thoughts on ice should not enter into the heat of debate.
There are horrible people who, instead of solving a problem, tangle it up and make it harder to solve for anyone who wants to deal with it. Whoever does not know how to hit the nail on the head should be asked not to hit it at all.