The human mind is not meant to be governed, certainly not by any book of rules yet written; it is supposed to run itself, and we are obliged to follow it along, trying to keep up with it as best we can.

I cannot think of a single field in biology or medicine in which we can claim genuine understanding, and it seems to me the more we learn about living creatures, especially ourselves, the stranger life becomes.

...the life of the planet began the long, slow process of modulating and regulating the physical conditions of the planet. The oxygen in today's atmosphere is almost entirely the result of photosynthetic living, which had its start with the appearance of blue-green algae among the microorganisms.

We have come a long way on that old molecule DNA.

We can take some gratification at having come a certain distance in just a few thousand years of our existence as language users, but it should be a deeper satisfaction, even an exhilaration, to recognize that we have such a distance still to go.

We habitually engage in meddling with nature. Until this century most of this meddling was good. Witness the preservation of the European countryside. But since then we've smoked it up and littered it and dumped too much in too many waters. I don't think it's our privilege to behave this way.

Doctors, dressed up in one professional costume or another, have been in busy practice since the earliest records of every culture on earth. It is hard to think of a more dependable or enduring occupation, harder still to imagine any future events leading to its extinction.