If you are asking me if my more global purpose is a battle against religion, it is.

If the universe were just electrons and selfish genes, meaningless tragedies ... are exactly what we should expect, along with equally meaningless good fortune. Such a universe would be neither evil nor good in intention ... The universe we observe has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil and no good, nothing but blind pitiless indifference.

For me, moral questions such as stem-cell research turn upon whether suffering is caused. In this case, clearly none is. The embryos have no nervous system. But that's not an issue discussed publicly. The issue is, Are they human? If you are an absolutist moralist, you say, "These cells are human, and therefore they deserve some kind of special moral treatment."

Time and again, my sociobiological colleagues have upbraided me as a turncoat, because I will not agree with them that the ultimate criterion for the success of a meme must be its contribution to Darwinian "fitness". At bottom, they insist, a "good meme" spreads because brains are receptive to it, and the receptiveness of brains is ultimately shaped by (genetic) natural selection.

The other way is the multiverse way. That says that maybe the universe we are in is one of a very large number of universes. The vast majority will not contain life because they have the wrong gravitational constant or the wrong this constant or that constant. But as the number of universes climbs, the odds mount that a tiny minority of universes will have the right fine-tuning.

The psychologist Elizabeth Loftus has shown great courage, in the face of spiteful vested interests, in demonstrating how easy it is for people to concoct memories that are entirely false but which seem, to the victim, every bit as real as true memories.

It's a flaw in our argument, for sure. By any reading of evolutionary theory, creationists ought to have died out ages ago. They serve no function in the planet's ecosystem, and no other species has survived so long while in such fundamental disagreement with observable reality. If I wasn't such an ardent believer in secular materialism, I'd wager this is really troubling Darwin in the afterlife.