It is precisely in knowing its limits that philosophy consists.

The greatest problem for the human species, the solution of which nature compels him to seek, is that of attaining a civil society which can administer justice universally.

Out of the crooked timber of humanity, no straight thing was ever made.

Great minds think for themselves.

But only he who, himself enlightened, is not afraid of shadows.

Reason must approach nature with the view, indeed, of receiving information from it, not, however, in the character of a pupil, who listens to all that his master chooses to tell him, but in that of a judge, who compels the witnesses to reply to those questions which he himself thinks fit to propose. To this single idea must the revolution be ascribed, by which, after groping in the dark for so many centuries, natural science was at length conducted into the path of certain progress.

Marriage...is the union of two people of different sexes with a view to the mutual possession of each other's sexual attributes for the duration of their lives.