To every separate person a thing is what he thinks it is – in other words, not a thing, but a think.

Helping other people is a drug so dangerous that there is no cure short of total abstention.

A word of advice. If, as a young man, student, you are tormented by a desire for women, it is best to get out into the fresh air as much as possible.

It is interesting to note that everyone has a different take on the world, a different opinion, and given the same inputs have completely different outputs.

Duty is what no-one else will do at the moment.

If they don't depend on true evidence, scientists are no better than gossips.

An unjust punishment is never forgotten.