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.

In Ireland, there are the same fossils, the same shells and the same sea bodies, as appear in America, and some of them are found in no other part of Europe.

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.

Nature is the system of laws established by the Creator for the existence of things and for the succession of creatures. Nature is not a thing, because this thing would be everything. Nature is not a creature, because this creature would be God. But one can consider it as an immense vital power, which encompasses all, which animates all, and which, subordinated to the power of the first Being, has begun to act only by his order, and still acts only by his concourse or consent ... Time, space and matter are its means, the universe its object, motion and life its goal.

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.

Time is the great workman of Nature.

The greatest marvel is not in the individual. It is in the succession, in the renewal and in the duration of the species that Nature would seem quite inconceivable. This power of producing its likeness that resides in animals and plants, this form of unity, always subsisting and appearing eternal, this procreative virtue which is perpetually expressed without ever being destroyed, is for us a mystery which, it seems, we will never be able to fathom.