That is an important distinction because it reminds us that advocates of full-blown liberty do not offer the world a problem-free society but "only" a society in which problems are discovered and problem-solvers are mobilized as quickly, fairly, and efficiently as impossible.

To get this point across to students in lectures, I used to quote the the title of a 1970 hit record: "I beg your pardon, I never promised you a rose garden." Social troubles will not disappear with the emergence of full freedom, but the chances of spotting and addressing them will be maximized in the most just way. That's the best we can hope for in a world of scarcity and uncertainty. On the other hand, that's not too shabby, is it?

What makes this happen? The answer can be captured in a single word: incentives. In a free society people are rewarded–they profit–by spotting and solving problems or correcting errors, before others have done so. Self-interest is further aligned with the interest of others.

This aspect of social life has been developed for many decades by the most important economists, among whom I would spotlight those of the Austrian school. In the 20th century they include Ludwig von Mises, F. A. Hayek, Israel Kirzner, and Murray Rothbard, followed by a couple of later generations of social scientists who continue to work in this tradition.

If the incentive system is to work, people need to be free to offer solutions. The scientist Joseph Priestley (1733–1804), in writing about education, wrote that to discover the best methods, we need an environment characterized by "unbounded liberty, and even caprice." As Priestley also put it, "Now, of all arts, those stand the fairest chance of being brought to perfection, in which there is opportunity of making the most experiments and trials." (I wrote about Priestley's radical advocacy of freedom in education in Freedom and School Choice in American Education.)