Those who are inspired by a model other than Nature, labor in vain.

In rivers, the water that you touch is the last of what has passed and the first of that which comes; so with present time.

To such an extent does nature delight and abound in variety that among her trees there is not one plant to be found which is exactly like another; and not only among the plants, but among the boughs, the leaves and the fruits, you will not find one which is exactly similar to another.

Everything comes from everything, and everything is made out of everything, and everything returns into everything.

It's easier to resist at the beginning than at the end.

I am not to blame for putting forward, in the course of my work on science, any general rule derived from a previous conclusion.

Nothing can be loved or hated unless it is first known.