“Though I myself am an atheist, I openly profess religion in the sense just mentioned, that is, a nature religion. I hate the idealism that wrenches man out of nature; I am not ashamed of my dependency on nature; I openly confess that the workings of nature affect not only my surface, my skin, my body, but also my core, my innermost being, that the air I breathe in bright weather has a salutary effect not only on my lungs but also on my mind, that the light of the sun illumines not only my eyes but also my spirit and my heart. And I do not, like a Christian, believe that such dependency is contrary to my true being or hope to be delivered from it. I know further that I am a finite moral being, that I shall one day cease to be. But I find this very natural and am therefore perfectly reconciled to the thought.”

“The power of thought is the light of knowledge, the power of will is the energy of character, the power of heart is love. Reason, love and power of will are perfections of man.”

“Christianity set itself the goal of fulfilling man’s unattainable desires, but for that very reason ignored his attainable desires. By promising man eternal life, it deprived him of temporal life, by teaching him to trust in God’s help it took away his trust in his own powers; by giving him faith in a better life in heaven, it destroyed his faith in a better life on earth and his striving to attain such a life. Christianity gave man what his imagination desires, but for that very reason failed to give him what he really and truly desires.”

“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.”

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

“To theology, … only what it holds sacred is true, whereas to philosophy, only what holds true is sacred.”