Every science consists in the coordination of facts; if the different observations were entirely isolated, there would be no science.

In mathematics we find the primitive source of rationality; and to mathematics must the biologists resort for means to carry out their researches.

Everything is relative; and only that is absolute.

All good intellects have repeated, since Bacon's time, that there can be no real knowledge but which is based on observed facts.

Know yourself to improve yourself.

nd now that man's history has been for the first time systematically considered as a whole, and has been found to be, like all other phenomena, subject to invariable laws, the preparatory labours of modern Science are ended.

Each department of knowledge passes through three stages. The theoretic stage; the theological stage and the metaphysical or abstract stage.