Pictures and shapes are but secondary objects and please or displease only in the memory.

There is no comparison between that which is lost by not succeeding and that which is lost by not trying.

The errors of young men are the ruin of business, but the errors of aged men amount to this, that more might have been done, or sooner.

The momentous thing in human life is the art of winning the soul to good or evil.

The human understanding is moved by those things most which strike and enter the mind simultaneously and suddenly, and so fill the imagination; and then it feigns and supposes all other things to be somehow, though it cannot see how, similar to those few things by which it is surrounded.

All artists are vain, they long to be recognized and to leave something to posterity. They want to be loved, and at the same time they want to be free. But nobody is free.

Observation and experiment for gathering material, induction and deduction for elaborating it: these are are only good intellectual tools.