If people should ever start to do only what is necessary millions would die of hunger.

Some people read only because they are too lazy to think.

I cannot say whether things will get better if we change; what I can say is they must change if they are to get better.

They do not think, therefore they are not.

If you are going to build something in the air it is always better to build castles than houses of cards.

Never undertake anything for which you wouldn't have the courage to ask the blessings of heaven.

So-called professional mathematicians have, in their reliance on the relative incapacity of the rest of mankind, acquired for themselves a reputation for profundity very similar to the reputation for sanctity possessed by theologians.