Humanity is part of nature, a species that evolved among other species. The more closely we identify ourselves with the rest of life, the more quickly we will be able to discover the sources of human sensibility and acquire the knowledge on which an enduring ethic, a sense of preferred direction, can be built.

It's obvious that the key problem facing humanity in the coming century is how to bring a better quality of life -- for 8 billion or more people -- without wrecking the environment entirely in the attempt.

Humanity is exalted not because we are so far above other living creatures, but because knowing them well elevates the very concept of life.

I am an optimist by nature. But I have to admit, it's getting kind of scary.

Nature holds the key to our aesthetic, intellectual, cognitive and even spiritual satisfaction.

Science is not marginal. Like art, it is a universal possession of humanity, and scientific knowledge has become a vital part of our species' repertory. It comprises what we know of the material world with reasonable certainty. . . . Thanks to science and technology, access to factual information of all kinds is rising exponentially.