The essence of any religion lies solely in the answer to the question: why do I exist, and what is my relationship to the infinite universe that surrounds me? It is impossible for there to be a person with no religion (i.e. without any kind of relationship to the world) as it is for there to be a person without a heart. He may not know that he has a religion, just as a person may not know that he has a heart, but it is no more possible for a person to exist without a religion than without a heart.

A man can live and be healthy without killing animals for food; therefore, if he eats meat, he participates in taking animal life merely for the sake of his appetite.

Here's my advice to you: don't marry until you can tell yourself that you've done all you could, and until you've stopped loving the women you've chosen, until you see her clearly, otherwise you'll be cruelly and irremediably mistaken. Marry when you're old and good for nothing...Otherwise all that's good and lofty in you will be lost.

…the majority of men do not think in order to know the truth, but in order to assure themselves that the life which they lead, and which is agreeable and habitual to them, is the one which coincides with the truth.

Boredom: the desire for desires.

But that had been grief--this was joy. Yet that grief and this joy were alike outside all the ordinary conditions of life; they were loopholes, as it were, in that ordinary life through which there came glimpses of something sublime. And in the contemplation of this sublime something the soul was exalted to inconceivable heights of which it had before had no conception, while reason lagged behind, unable to keep up with it.

The teaching of the church, theoretically astute, is a lie in practice and a compound of vulgar superstitions and sorcery.