The defining challenge of the 21st century will be to face the reality that humanity shares a common fate on a crowded planet.

We had a booming stock market in 1929 and then went into the world's greatest depression. We have a booming stock market in 1999. Will the bubble somehow burst, and then we enter depression? Well, some things are not different.

I believe myself that there's a great deal more interest and engagement among Americans than our politicians recognize.

If we did go into a recession, something that's always possible for the U.S. or Europe, we could lower interest rates and expand the money supply without worrying about the price of gold.

It's the American leadership that has not played the role it should be playing and that leaders in other countries have been playing.

The key to ending extreme poverty is to enable the poorest of the poor to get their foot on the ladder of development. The ladder of development hovers overhead, and the poorest of the poor are stuck beneath it. They lack the minimum amount of capital necessary to get a foothold, and therefore need a boost up to the first rung.

The essence of Africa's crisis is fundamentally its extreme poverty and therefore its inability to mobilize out of its own resources even the barest of minimum resources to address any of the public health crises that Africa faces.