(On the temperature of water in wells) The reason why the water in wells becomes colder in summer is that the earth is then rarefied by the heat, and releases into the air all the heat-particles it happens to have. So, the more the earth is drained of heat, the colder becomes the moisture that is concealed in the ground. On the other hand, when all the earth condenses and contracts and congeals with the cold, then, of course, as it contracts, it squeezes out into the wells whatever heat it holds.

Fear is the mother of all gods.

Were a man to order his life by the rules of true reason, a frugal substance joined to a contented mind is for him great riches; for never is there any lack of a little.

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.

Some species increase, others diminish, and in a short space the generations of living creatures are changed and, like runners, pass on the torch of life.

What can give us more sure knowledge than our senses? How else can we distinguish between the true and the false?

Certainly it was no design of the atoms to place themselves in a particular order, nor did they decide what motions each should have. But atoms were struck with blows in many ways and carried along by their own weight from infinite times up to the present. They have been accustomed to move and to meet in all manner of ways. For this reason, it came to pass that being spread abroad through a vast time and trying every sort of combination and motion, at length those come together that produce great things, like earth and sea and sky and the generation of living creatures.