I worry that track is going to enter into an impossibly complicated stage, where our understanding of the complexities of human physiology - and our ability to accentuate and exploit them - is going to make the notion of pure competition impossible.

So long as the stereotype is used as a way of understanding how to fix the problem as opposed to demonizing a people or writing them off, then I think it's OK.

Often a sign of expertise is noticing what doesn't happen.

We spend a lot of time and effort trying to figure out who's going to be a good NFL quarterback, and we do a very bad job of it. We don't really know. And we also spend a lot of time trying to figure out who will be a good teacher, and we're really bad at that too. We don't know if someone is going to be a good teacher when they start teaching. So what should we do in those situations in which predictions are useless?

There will be statues of Bill Gates across the Third World. There's a reasonable shot that - because of his money - we will cure malaria.

An aggressive drug-testing program would cut down on certain abuses, but its never going to catch everyone - or even close to everyone.

The key to good decision making is not knowledge... It's whether our work fulfills us.