In his book A Conflict of Visions, Thomas Sowell argues that a good deal of political disagreements can be traced back to different assumptions about human nature. It is not a coincidence if many people seem to systematically fall on the same side of different, apparently unrelated political issues: starting from different visions of human nature and how the world works, people seem to cluster around the same stable sets of political positions (with the help, I would surmise, of some good old tribalism). Sowell distinguishes between the unconstrained vision and the constrained vision. In the unconstrained vision, human beings are capable of great feats of wisdom, virtue, and intellectual power. Our egoism, our self-interestedness, and our wickedness are not part of our nature, but are instead artifacts of cruel, unfair, or irrational institutions. Given our capacity for enlightenment, it follows that some of us, who find themselves further on the path of perfectibility, can use their intellectual and moral power to elucidate what must be done and get rid of the shackles of the …