The painter strives and competes with nature.

It vexes me greatly that having to earn my living has forced me to interrupt the work and to attend to small matters.

Avoid studies of which the result dies with the worker.

He who does not understand the supreme certainty of mathematics is wallowing in confusion.

Of the four elements water is the second in weight and the second in respect of mobility. It is never at rest until it unites with the sea.

Those who condemn the supreme certainty of mathematics feed on confusion, and can never silence the contradictions of the sophistical sciences which lead to eternal quackery.

A clever man without wisdom is like a beautiful flower without fragrance.