Adam Smith's uncritically enthusiastic modern disciples portray his invisible hand theory as saying that market forces reliably harness selfish individuals to serve the common good. That's often true, but as Darwin recognized clearly, many traits that serve the interests of individual animals make life more difficult for larger groups.

When people bump up against one another in the course of pursuing their goals, it is in everyone's interest to resolve any resulting problems in the least costly ways possible.

Only the federal government has the power to spend beyond its current revenue. It shouldn't do that when the economy is at full employment. But it's an essential step for an economy mired in recession.

In short both the things we feel we need and the things available for us to buy depend largely—beyond some point, almost entirely—on the things that others choose to buy.

As John Maynard Keynes taught us in the 1930s, in such situations, government is the only entity with both the motive and the ability to boost total spending by enough to put people back to work. As it happens there are long lists of important public projects that cry out to be done.

The link between rational individual behavior and collectively desirable outcomes is extremely tenuous.

Life is graded on the curve. It's not how big you are, how strong you are, how smart you are. It's how good you are at the things that count relative to the people around you.