The opposing view, that man is (at least somewhat) perfectible, or that the evil in the world is mainly the result of bad social institutions has been the view of Godwin, Rousseau, John Stuart Mill, Thomas Paine, Jefferson, Voltaire, Ronald Dworkin, and John Kenneth Galbraith. The constrained vision has been characterized as cynical, conservative, pessimistic, as opposed to the romantic, liberal, optimistic, idealistic unconstrained vision of man. Sowell points out that the person's view of human nature often serves as a litmus test that can predict which side of a given controversy the person will come down on, with holders of the constrained vision opposing holders of the unconstrained view across a spectrum of religious, social, and political issues. Often, people at opposite poles have great difficulty communicating with and understanding each other, since their basic premises are so different.
Mark me on the "constrained" side.
bump
Perhaps its my own shortcoming, but I've always thought of Liberals as sincere, and well intentioned. But that they view life and its participants through a 'utopia-is-possible' prism. For all their ballyhooed intellect, I would not expect to hear such analysis as this from them.