I will argue that every scrap of biological diversity is priceless, to be learned and cherished, and never to be surrendered without a struggle.

The human juggernaut is permanently eroding Earth's ancient biosphere.

That is the great mystery of human evolution: how to account for calculus and Mozart.

The most dangerous of devotions, in my opinion, is the one endemic to Christianity: I was not born to be of this world. With a second life waiting, suffering can be endured - especially in other people. The natural environment can be used up. Enemies of the faith can be savaged and suicidal martyrdom praised.

It often occurs to me that if, against all odds, there is a judgmental God and heaven, it will come to pass that when the pearly gates open, those who had the valor to think for themselves will be escorted to the head of the line, garlanded, and given their own personal audience.

Individual versus group selection results in a mix of altruism and selfishness, of virtue and sin, among the members of a society. If one colony member devotes its life to service over marriage, the individual is of benefit to the society, even though it does not have personal offspring. A soldier going into battle will benefit his country, but he runs a higher risk of death than one who does not. An altruist benefits the group, but a layabout or coward who saves his own energy and reduces his bodily risk passes the resulting social cost to others.

While ants exist in just the right numbers for the rest of the living world, humans have become too numerous. If we were to vanish today, the land environment would return to the fertile balance that existed before the human population explosion. Only a dozen or so species, among which are the crab louse and a mite that lives in the oil glands of our foreheads, depend on us entirely. But if ants were to disappear, tens of thousands of other plants and animal species would perish also, simplifying and weakening land ecosystems almost everywhere.