A celibate clergy is an especially good idea, because it tends to suppress any hereditary propensity toward fanaticism.

Is it fair to be suspicious of an entire profession because of a few bad apples? There are at least two important differences, it seems to me. First, no one doubts that science actually works, whatever mistaken and fraudulent claim may from time to time be offered. But whether there are any miraculous cures from faith-healing, beyond the body's own ability to cure itself, is very much at issue. Secondly, the expose' of fraud and error in science is made almost exclusively by science. But the exposure of fraud and error in faith-healing is almost never done by other faith-healers.

The vast distances that separate the stars are providential. Beings and worlds are quarantined from one another. The quarantine is lifted only for those with sufficient self-knowledge and judgment to have safely traveled from star to star.

And after we returned to the savannahs and abandoned the trees, did we long for those great graceful leaps and ecstatic moments of weightlessness in the shafts of sunlight of the forest roof?

Eratosthenes's only tools were sticks, eyes, feet, and brains; plus a zest for experiment. With those tools he correctly deduced the circumference of the Earth, to high precision, with an error of only a few percent. That's pretty good figuring for 2200 years ago.

The truth may be puzzling. It may take some work to grapple with. It may be counterintuitive. It may contradict deeply held prejudices. It may not be consonant with what we desperately want to be true. But our preferences do not determine what's true.

One of the saddest lessons of history is this: If we’ve been bamboozled long enough, we tend to reject any evidence of the bamboozle. We’re no longer interested in finding out the truth. The bamboozle has captured us. It’s simply too painful to acknowledge, even to ourselves, that we’ve been taken. Once you give a charlatan power over you, you almost never get it back.