Our greatest enemies, the ones we must fight most often, are within.

The balance of power is the scale of peace.

The American constitutions were to liberty, what a grammar is to language: they define its parts of speech, and practically construct them into syntax

That which is now called natural philosophy, embracing the whole circle of science, of which astronomy occupies the chief place, is the study of the works of God, and of the power and wisdom of God in his works, and is the true theology.

As to the Christian system of faith, it appears to me as a species of Atheism — a sort of religious denial of God. It professes to believe in a man rather than in God. It is a compound made up chiefly of Manism with but little Deism, and is as near to Atheism as twilight is to darkness. It introduces between man and his Maker an opaque body, which it calls a Redeemer, as the moon introduces her opaque self between the earth and the sun, and it produces by this means a religious, or an irreligious, eclipse of light. It has put the whole orbit of reason into shade.

A body of men holding themselves accountable to nobody ought not to be trusted by anybody.

Truth never envelops itself in mystery, and the mystery in which it is at any time enveloped is the work of its antagonist, and never of itself.