The law is this: that each of our leading conceptions-each branch of our knowledge-passes successively through three different theoretical conditions: the Theological, or fictitious: the Metaphysical, or abstract; and the Scientific, or positive.

Humanity is always made up of more dead than living.

The heavens declare the glory of Kepler and Newton.

Men are not allowed to think freely about chemistry and biology: why should they be allowed to think freely about political philosophy?

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

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

Induction for deduction, with a view to construction.