Sigmund Freud often remarked that great revolutions in the history of science have but one common, and ironic, feature: they knock human arrogance off one pedestal after another of our previous conviction about our own self-importance.

In what I like to call the Great Asymmetry, every spectacular incident of evil will be balanced by 10,000 acts of kindness, too often unnoted and invisible.

Without a commitment to science and rationality in its proper domain, there can be no solution to the problems that engulf us. Still, the Yahoos never rest.

Forelimbs of people, porpoises, bats and horses provide the classic example of homology in most textbooks. They look different, and do different things, but are built of the same bones. No engineer, starting from scratch each time, would have built such disparate structures from the same parts.

Darwin's principle of natural selection leads to the prediction that the proper way to analyze any evolutionary development is to see the new features as adaptive to environments. And that's a perfectly good principle. The problem is that there are many evolutionary biologists who view everything that happens in evolution as directly evolved for adaptive benefit. And that just doesn't work. Whenever you build a structure for adaptive reasons, the structure is going to exhibit properties that have nothing to do with adaptation. They're just side consequences.

We pass through this world but once.

But our ways of learning about the world are strongly influenced by the social preconceptions and biased modes of thinking that each scientist must apply to any problem. The stereotype of a fully rational and objective scientific method, with individual scientists as logical (and interchangeable) robots, is self-serving mythology.