The two major challenges for the 21st century are to improve the economic situation of the majority and save as much of the planet as we can.

Every ecosystem, even a small one, is sustainable because it has certain ensembles and conditions and influences that are unique to it. And the biological ensembles are almost certainly, even the most modest ones, in the thousands of species. We don't know what's involved in the models - not even the beginnings. And yet we're trying to make a sustainable world, which has to include the natural world. The human species is triumphant, but it's got to get a grip. It's got to come to understand what's happened, why we're this way and what we're doing.

The world depends on fungi, because they are major players in the cycling of materials and energy around the world.

Every major religion today is a winner in the Darwinian struggle waged among cultures, and none ever flourished by tolerating its rivals.

There is no better high than discovery.

The cutting of primeval forest and other disasters, fueled by the demands of growing human populations, are the overriding threat to biological diversity everywhere.

The vast majority of species that are vanishing, we haven't even discovered yet. How can you possibly put them back in nature if the ecosystem is gone?