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

To understand a science, it is necessary to know its history.

Indeed, every true science has for its object the determination of certain phenomena by means of others, in accordance with the relations which exist between them.

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

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