The source of man's unhappiness is his ignorance of Nature.

How could the human mind progress, while tormented with frightful phantoms, and guided by men, interested in perpetuating its ignorance and fears? Man has been forced to vegetate in his primitive stupidity: he has been taught stories about invisible powers upon whom his happiness was supposed to depend. Occupied solely by his fears, and by unintelligible reveries, he has always been at the mercy of priests, who have reserved to themselves the right of thinking for him, and of directing his actions.

The unhappiness of people is due to their ignorance of nature.

Religion has ever filled the mind of man with darkness, and kept him in ignorance of his real duties and true interests. It is by dispelling the clouds and phantoms of religion, that we shall discover truth, morality and reason. Religion diverts us from the causes of evils, and from these remedies which nature advocates, far from curing; it only aggravates, perpetuates and multiplies them.

If we go back to the beginnings of things, we shall always find that ignorance and fear created the gods; that imagination, rapture and deception embellished them; that weakness worships them; that custom spares them; and that tyranny favors them in order to profit from the blindness of men.

Nature, you say, is totally inexplicable without a God. That is to say, to explain what you understand very little, you have need of a cause which you understand not at all.

The Jehovah of the Jews is a suspicious tyrant, who breathes nothing but blood, murder, and carnage, and who demands that they should nourish him with the vapours of animals. The Jupiter of the Pagans is a lascivious monster. The Moloch of the Phoenicians is a cannibal. The pure mind of the Christians resolved, in order to appease his fury, to crucify his own son. The savage god of the Mexicans cannot be satisfied without thousands of mortals which are immolated to his sanguinary appetite.