Poor humanity, to saddle the gods with such a responsibility and throw in a vindictive temper. What griefs they hatch for themselves, what festering sores for us, what tears for our prosperity! This is not piety, this oft-repeated show of bowing a veiled head before a graven image; this bustling to every altar; this kow-towing and prostration on the ground with palms outspread before the shrines of the gods; this deluging of vow on vow. True piety lies rather in the power to contemplate the universe with a quiet mind.

Constant dripping hollows out a stone.

What came from the earth returns back to the earth, and the spirit that was sent from heaven, again carried back, is received into the temple of heaven.

[N]ature repairs one thing from another and allows nothing to be born without the aid of another's death.

The mind like a sick body can be healed and changed by medicine.

True piety lies rather in the power to contemplate the universe with a quiet mind.

It was certainly not by design that the particles fell into order, they did not work out what they were going to do, but because many of them by many chances struck one another in the course of infinite time and encountered every possible form and movement, that they found at last the disposition they have, and that is how the universe was created.