The sovereign is called a tyrant who knows no laws but his caprice.

One always speaks badly when one has nothing to say.

The greatest consolation in life is to say what one thinks.

Descartes constructed as noble a road of science, from the point at which he found geometry to that to which he carried it, as Newton himself did after him. ... He carried this spirit of geometry and invention into optics, which under him became a completely new art.

Sensual pleasure passes and vanishes, but the friendship between us, the mutual confidence, the delight of the heart, the enchantment of the soul, these things do not perish and can never be destroyed.

It is not the answers you give, but the questions you ask.

Nature has always had more force than education.