It is not so bad being ignorant if you are totally ignorant; the hard thing is knowing in some detail the reality of ignorance.

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.

The greatest of all the accomplishments of 20th century science has been the discovery of human ignorance

Mistakes are at the very base of human thought, embedded there, feeding the structure like root nodules. If we were not provided with the knack for being wrong, we could never get anything useful done. We think our way along by choosing between right and wrong alternatives, and the wrong choices have to be made as often as the right ones. We get along in life this way.

A lot of people fear death because they think that so overwhelming an experience has to be painful, but I've seen quite a few deaths, and, with one exception, I've never known anyone to undergo anything like agony. That's amazing when you think about it. I mean, how complicated the mechanism is that's being taken apart.

As a species, taking all in all, we are still too young, too juvenile, to be trusted. We have spread across the face of the earth in just a few thousand years, no time at all as evolution clocks time, covering all livable parts of the planet, endangering other forms of life, and now threatening ourselves.

...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.