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

Language forms a kind of wealth, which all can make use of at once without causing any diminution of the store, and which thus admits a complete community of enjoyment; for all, freely participating in the general treasure, unconsciously aid in its preservation.

The sacred formula of positivism: love as a principle, the order as a foundation, and progress as a goal.

Humanity is always made up of more dead than living.

The only real life is the collective life of the race; individual life has no existence except as an abstraction.

The dead govern the living.

Every attempt to employ mathematical methods in the study of chemical questions must be considered profoundly irrational and contrary to the spirit of chemistry.... if mathematical analysis should ever hold a prominent place in chemistry -- an aberration which is happily almost impossible -- it would occasion a rapid and widespread degeneration of that science.