Answer by taking a quote from the following article:

Thomas Sowell (; born June 30, 1930) is an American economist, social theorist, political philosopher, and author. He is currently Senior Fellow at the Hoover Institution, Stanford University. Sowell was born in North Carolina, but grew up in Harlem, New York.

Sowell has also written a trilogy of books on ideologies and political positions, including A Conflict of Visions, where he speaks about the origins of political strife; The Vision of the Anointed, where he compares the conservative/libertarian and liberal/progressive worldviews; and The Quest for Cosmic Justice, where, as in many of his other writings, he outlines his thesis of the need for intellectuals, politicians and leaders to fix and perfect the world in utopian, and ultimately he posits, disastrous fashions. Separate from the trilogy, but also in discussion of the subject, he wrote Intellectuals and Society, where, building on his earlier work, he discusses what he argues to be the blind hubris and follies of intellectuals in a variety of areas.  Sowell challenges the notion that black progress is due to progressive government programs or policies, in The Economics and Politics of Race, (1983), Ethnic America (1981), Affirmative Action Around the World (2004), and other books. He claims that many problems identified with blacks in modern society are not unique, either in terms of American ethnic groups, or in terms of a rural proletariat struggling with disruption as it became urbanized, as discussed in his book Black Rednecks and White Liberals (2005).  In Affirmative Action Around the World Sowell holds that affirmative action covers most of the American population, particularly women, and has long since ceased to favor blacks.  Sowell described his serious study of Karl Marx in his autobiography. He opposes Marxism, providing a critique in his book Marxism: Philosophy and Economics (2011).  Sowell also favors decriminalization of all drugs.

How did his books sale