The great paradox of determinism and free will, which has held the attention of the wisest of philosophers and psychologists for generations, can be phrased in more biological terms as follows: If our genes are inherited, and our environment is a train of physical events set in motion before we were born, how can there be a truly independent agent within the brain? The agent itself is created by the interaction of the genes and the environment. It would appear that our freedom is only a self delusion.

I turned to the teeming small creatures that can be held between the thumb and forefinger: the little things that compose the foundation of our ecosystems, the little things, as I like to say, who run the world.

If those committed to the quest fail, they will be forgiven. When lost, they will find another way. The moral imperative of humanism is the endeavor alone, whether successful or not, provided the effort is honorable and failure memorable.

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.

The worst thing that will probably happen-in fact is already well underway-is not energy depletion, economic collapse, conventional war, or the expansion of totalitarian governments. As terrible as these catastrophes would be for us, they can be repaired in a few generations. The one process now going on that will take millions of years to correct is loss of genetic and species diversity by the destruction of natural habitats. This is the folly our descendants are least likely to forgive us.

If you go from the USA - which, relative to the rest of the world, is in pretty good shape in terms of biodiversity and sustainability - to the tropics, everything gets worse. You have Indonesia, which is destroying its own forest. In West Africa there's no control whatsoever. It's a global situation. For that reason it ties in clearly with the needs and relationships of low-income countries.

Consider the nematode roundworm, the most abundant of all animals. Four out of five animals on Earth are nematode worms — if all solid materials except nematode worms were to be eliminated, you could still see the ghostly outline of most of it in nematode worms.