In this book, which the author calls a "culmination of thirty years of work in the history of ideas," Sowell attempts to explain the ideological difference between liberals and conservatives as a disagreement over the moral potential inherent in nature. Those who see that potential as limited prefer to constrain governmental authority, he argues. They feel that reform is difficult and often dangerous, and put their faith in family, custom, law, and traditional institutions. Conversely, those who have faith in human nature prefer to remove institutional and traditional constraints. Controversies over such diverse issues as criminal justice, income distribution, or war and peace repeatedly show an ideological divide along the lines of these two conflicting visions.