In short, we all have grossly inadequate knowledge in other people's specialties.

The idea that everything must "justify itself before the bar of reason" goes back at least as far as the 18th century. But that just makes it a candidate for the longest-running fallacy in the world.

Given the high degree of specialization in a modern economy, demanding that everything "justify itself before the bar of reason" means demanding that people who know what they are doing must be subject to the veto of people who don't have a clue about the decisions that they are second-guessing.

It means demanding that ignorance override knowledge.

The ignorant are not just some separate group of people. As Will Rogers said, everybody is ignorant, but just about different things.

Should computer experts tell brain surgeons how to do their job? Or horse trainers tell either of them what to do?

One of the reasons why central planning sounds so good, but has failed so badly that even socialist and communist governments finally abandoned the idea by the end of the 20th century, is that nobody knows enough to second guess everybody else.

Every time oil prices shoot up, there are cries of "greed" and demands by politicians for an investigation of collusion by Big Oil. There have been more than a dozen investigations of oil companies over the years, and none of them has turned up the collusion that is supposed to be responsible for high gas prices.

Now that oil prices have dropped big time, does that mean that oil companies have lost their "greed"? Or could it all be supply and demand -- a cause and effect explanation that seems to be harder for some people to understand than emotions like "greed"?