I study myself more than any other subject. That is my metaphysics, that is my physics.

The bees pillage the flowers here and there but they make honey of them which is all their own; it is no longer thyme or marjolaine: so the pieces borrowed from others he will transform and mix up into a work all his own.

One man may have some special knowledge at first-hand about the character of a river or a spring, who otherwise knows only what everyone else knows. Yet to give currency to this shred of information, he will undertake to write on the whole science of physics. From this fault many great troubles spring.

There is nothing useless in nature; not even uselessness itself

Opinion is a powerful party, bold, and without measure.

No pleasure is fully delightful without communications, and no delight absolute except imparted.

An ancient father says that a dog we know is better company than a man whose language we do not understand.