Only well-written works will descend to posterity. Fulness of knowledge, interesting facts, even useful inventions, are no pledge of immortality, for they may be employed by more skilful hands; they are outside the man; the style is the man himself.

The discoveries that one can make with the microscope amount to very little, for one sees with the mind's eye and without the microscope the real existence of all these little beings.

The human mind cannot create anything. It produces nothing until having been fertilized by experience and meditation; its acquisitions are the germs of its production.

The cat is the only animal which accepts the comforts but rejects the bondage of domesticity.

Man thinks, and at once becomes the master of the beings that do not think.

To write well is to think well, to feel well, and to render well; it is to possess at once intellect, soul, and taste.

All the work of the crystallographers serves only to demonstrate that there is only variety everywhere where they suppose uniformity ... that in nature there is nothing absolute, nothing perfectly regular.