The primary question about life after death is not whether it is a fact, but even if it is, what problems that really solves. - Ludwig Wittgenstein

A teacher who can show good, or indeed astounding results while he is teaching, is still not on that account a good teacher, for it may be that, while his pupils are under his immediate influence, he raises them to a level which is not natural to them, without developing their own capacities for work at this level, so that they immediately decline again once the teacher leaves the schoolroom.

That of which we cannot speak, we must pass over in silence

Telling someone something that he does not understand is pointless, even if you add that he will not understand it. (That so often happens with someone you love.) If you have a room which you do not want certain people to get into, put a lock on it for which they do not have the key. But there is no point in talking to them about it, unless of course you want them to admire the room from the outside!

The honourable thing to do is to put a lock on the door which will be noticed only by those who can open it, not by the rest.