The irrationality of disgust suggests it is unreliable as a source of moral insight. There may be good arguments against gay marriage, partial-birth abortions and human cloning, but the fact that some people find such acts to be disgusting should carry no weight.

Some scholars argue that although the brain might contain neural subsystems, or modules, specialized for tasks like recognizing faces and understanding language, it also contains a part that constitutes a person, a self: the chief executive of all the subsystems.

Morality is often seen as an innovation, like agriculture and writing. From this perspective, babies are pint-sized psychopaths, self-interested beings who need to be taught moral notions such as the wrongness of harming another person.

Part of the satisfaction of tattling surely comes from showing oneself to adults as a good moral agent, a responsible being who is sensitive to right and wrong. But I would bet that children would tattle even if they could do so only anonymously. They would do it just to have justice done.

Today the biggest problem in caring for those with AIDS is no longer mainly a medical or scientific problem. The crisis is access to affordable drugs.

I'm not much of a math and science guy. I spent most of my time in school daydreaming and managed to turn it into a living.

The scientific man does not aim at an immediate result. He does not expect that his advanced ideas will be readily taken up. His work is like that of the planter - for the future. His duty is to lay the foundation for those who are to come, and point the way.

The science of being healthy is well-known. It is not esoteric. There are no magic bullets. If you want to live a long life, we’ve known the answers for more than a hundred years. It’s a wide-ranging diet with as much fruit and veg as you can stuff into yourself, and plenty of exercise. It doesn't even matter what kind of exercise."