Good applied science in medicine, as in physics, requires a high degree of certainty about the basic facts at hand, and especially about their meaning, and we have not yet reached this point for most of medicine.

Ants are so much like human beings as to be an embarrassment. They farm fungi, raise aphids as livestock, launch armies into wars, use chemical sprays to alarm and confuse enemies, capture slaves... They do everything but watch television.

I don't think that the permanence of the individual human soul is an indispensable part of religious thought.

Viewed from the distance of the moon, the astonishing thing about the earth, catching the breath, is that it is alive. ... It has the organized, self-contained look of a live creature, full of information, marvelously skilled in handling the sun

The central task of science is to arrive, stage by stage, at a clearer comprehension of nature, but this does not at all mean, as it is sometimes claimed to mean, a search for mastery over nature.

As evolutionary time is measured, we have only just turned up and have hardly had time to catch breath, still marveling at our thumbs, still learning to use the brand-new gift of language. Being so young, we can be excused all sorts of folly and can permit ourselves the hope that someday, as a species, we will begin to grow up.

I agree that you might clone some people who would look amazingly like their parental cell donors, but the odds are that they'd be almost as different as you or me, and certainly more different than any of today's identical twins.