Editor's note: This is Part IV in a series. Part I can be found here. Part II can be found here. Part III can be found here.

Among the many irrational ideas about racial and ethnic groups that have polarized societies over the centuries and around the world, few have been more irrational and counterproductive than the current dogmas of multiculturalism.

Intellectuals who imagine that they are helping racial or ethnic groups that lag behind by redefining their lags out of existence with multicultural rhetoric are in fact leading them into a blind alley.

Multiculturalism is a tempting quick fix for groups that lag by simply pronouncing their cultures to be equal, or "equally valid," in some vague and lofty sense. Cultural features are just different, not better or worse, according to this dogma.

Yet the borrowing of particular features from other cultures -- such as Arabic numerals that replaced Roman numerals, even in Western cultures that derived from Rome -- implies that some features are not simply different but better, including numbers. Some of the most advanced cultures in history have borrowed from other cultures, because no given collection of human beings has created the best answers to all the questions of life.

Nevertheless, since multiculturalists see all cultures as equal or "equally valid," they see no justification for schools to insist that black children learn standard English, for example. Instead, each group is encouraged to cling to its own culture and to take pride in its own past glories, real or imaginary.

In other words, members of minority groups that lag educationally, economically or otherwise are to continue to behave in the future as they have in the past -- and, if they do not get the same outcomes as others, it is society's fault. That is the bottom line message of multiculturalism.

George Orwell once said that some ideas are so foolish that only an intellectual could believe them. Multiculturalism is one of those ideas. The intelligentsia burst into indignation or outrage at "gaps" or "disparities" in educational, economic or other outcomes -- and denounce any cultural explanation of these group differences as "blaming the victim."

There is no question that some races or whole nations have been victimized by others, any more than there is any question that cancers can cause death. But that is very different from saying that deaths can automatically be blamed on cancer. You might think that intellectuals could make that distinction. But many do not.

Yet intellectuals see themselves as friends, allies and defenders of racial minorities, even as they paint them into a corner of cultural stagnation. This allows the intelligentsia to flatter themselves that they are on the side of the angels against the forces of evil that are conspiring to keep minorities down.

When they cannot come up with hard evidence in any particular case to support this theory today, that just proves to the intelligentsia how fiendishly clever and covert these pervasive efforts to hold down minorities are.

Why people with high levels of mental skills and rhetorical talents would tie themselves into knots with such reasoning is a mystery. Perhaps it is just that they cannot give up a social vision that is so flattering to themselves, despite how detrimental it may be to the people they claim to be helping.

Multiculturalism, like the caste system, paints people into the corner where they happened to have been born. But at least the caste system does not claim to benefit those at the bottom.

Multiculturalism not only serves the ego interests of intellectuals, it serves the political interests of elected officials, who have every incentive to promote a sense of victimhood, and even paranoia, among groups whose votes they want, in exchange for both material and psychic support.

The multicultural vision of the world also serves the interests of those in the media, who thrive on moral melodramas. So do whole departments of ethnic "studies" in academia and a whole industry of "diversity" consultants, community organizers and miscellaneous other race hustlers.

The biggest losers in all this are those members of racial minorities who allow themselves to be led into the blind alley of resentment and rage, even when there are broad avenues of opportunity available. And we all lose when society is polarized.