There have always been ignorant people, but they haven't always had college degrees to make them unaware of their ignorance. Some people imagine that they are well informed because they have memorized a whole galaxy of trendy dogmas and fashionable attitudes.

Should a professor of accounting or chemistry be fired for using up class time to sound off about homelessness or the war in Iraq? Yes! There is no high moral principle that prevents it. What prevents it are tenure rules that have saddled so many colleges with so many self-indulgent prima donnas who seem to think that they are philosopher kings, when in fact they are often grossly ignorant or misinformed outside the narrow confines of their particular specialty.

People who are very aware that they have more knowledge than the average person are often very unaware that they do not have one-tenth of the knowledge of all of the average persons put together. In this situation, for the intelligentsia to impose their notions on ordinary people is essentially to impose ignorance on knowledge.

People who know nothing about advertising, nothing about pharmaceuticals, and nothing about economics have been loudly proclaiming that the drug companies spend too much on advertising - and demanding that the government pass laws based on their ignorance.

In a democracy, we have always had to worry about the ignorance of the uneducated. Today we have to worry about the ignorance of people with college degrees.

Of all ignorance, the ignorance of the educated is the most dangerous. Not only are educated people likely to have more influence, they are the last people to suspect that they don't know what they are talking about when they go outside their narrow fields.