Their vain presumption of knowing all can take beginning solely from their never having known anything; for if one has but once experienced the perfect knowledge of one thing, and truly tasted what it is to know, he shall perceive that of infinite other conclusions he understands not so much as one.

Mathematics is the key and door to the sciences.

The Universe is a grand book which cannot be read until one first learns to comprehend the language and become familiar with the characters in which it is composed. It is written in the language of mathematics.

Knowing thyself, that is the greatest wisdom.

They who depend upon manifest observations will philosophize better than those who persist in opinions repugnant to the senses.

Nature...does not act by means of many things when it can do so by means of a few.

Two truths cannot contradict one another.