If therefore my work is negative, irreligious, atheistic, let it be remembered that atheism — at least in the sense of this work — is the secret of religion itself; that religion itself, not indeed on the surface, but fundamentally, not in intention or according to its own supposition, but in its heart, in its essence, believes in nothing else than the truth and divinity of human nature.

It is not as in the Bible, that God created man in his own image. But, on the contrary, man created God in his own image.

I would rather be a devil in alliance with truth, than an angel in alliance with falsehood.

For the religious the holy is truth, for the philosophic the truth is holy.

What yesterday was still religion is no longer such today; and what today is atheism, tomorrow will be religion.

As we expand our knowledge of good books, we shrink the circle of men whose company we appreciate.

Only he is a truly ethical, a truly human being, who has the courage to see through his own religious feelings and needs.