Thomas Sowell‘s latest column at National Review Online reminds readers of the distinction between higher tax rates and higher tax revenue collection.

It is one of the many signs of the mindlessness of our times that all sorts of people declare that “the rich” are not paying their “fair share” in taxes, without telling us concretely what they mean by either “the rich” or “fair share.”

Whether in politics or in the media, words are increasingly used, not to convey facts or even allegations of facts, but simply to arouse emotions. Undefined words are a big handicap in logic, but they are a big plus in politics, where the goal is not clarity but victory — and the votes of gullible people count just as much as the votes of people who have common sense.

What a “fair share” of taxes means in practice is simply “more.” No matter how high the tax rate is on people with a given income, you can always raise the tax rate further by saying that they are still not paying their “fair share.”

Advocates of higher tax rates can get very specific when they want to. A recent article in the New York Times says that raising the tax rate on the top one percent of income earners to 40 percent would generate “about $157 billion” a year in additional tax revenue for the government.

This ignores mountains of evidence, going back for generations, showing that raising tax rates does not automatically mean raising tax revenues — and has often actually led to falling tax revenues. A fantasy expressed in numbers is still a fantasy.