Human existence may be simpler than we thought. There is no predestination, no unfathomed mystery of life. Demons and gods do not vie for our allegiance. Instead, we are self-made, independent, alone, and fragile, a biological species adapted to live in a biological world. What counts for long-term survival is intelligent self-understanding, based upon a greater independence of thought than that tolerated today even in our most advanced democratic societies.

Of course, there is no reconciliation between the theory of evolution by natural selection and the traditional religious view of the origin of the human mind.

Biology has finally opened up to achieve a unifying embrace of all its disciplines. We're seeing the renaissance of what could be called scientific natural history, which makes available the groundwork - the foundation work - of what is actually on the Earth.

To be anthropocentric is to remain unaware of the limits of human nature, the significance of biological processes underlying human behavior, and the deeper meaning of long-term genetic evolution.

If insemination were the sole biological function of sex, it could be achieved far more economically in a few seconds of mounting and insertion. Indeed, the least social of mammals mate with scarcely more ceremony. The species that have evolved long-term bonds are also, by and large, the ones that rely on elaborate courtship rituals. . . . Love and sex do indeed go together.

Hands-on experience at the critical time, not systematic knowledge, is what counts in the making of a naturalist. Better to be an untutored savage for a while, not to know the names or anatomical detail. Better to spend stretches of time just searching and dreaming.

People need a sacred narrative. They must have a sense of larger purpose, in one form or another, however intellectualized. They will find a way to keep ancestral spirits alive.