But what is it that we have learned that is truly new about human nature in the 20th century? I submit that the body of even the best work consists overwhelmingly of commentary on insights first expressed centuries ago. Indeed, if I were to characterize the role of the behavioral sciences in the 20th century—and please take this as a provisional and sweeping statement that needs a lot of work—it would be as follows: The first three-quarters of the 20th century were spent largely trying to make observed human behavior compatible with theoretical schemes that ultimately didn’t work. The last quarter of the 20th century marks the beginning of a painful, slow reconciliation of what modern behavioral science tells us empirically with what the ancients told us, and an even more painful repudiation of the 20th century’s favorite conceits. Where does Freudianism, its intellectual position so commanding fifty years ago, stand today? Remnants are left, but only remnants. I shouldn’t even mention Marxism; it is too easy a target. But the fact remains: For decades, it was the leading intellectual paradigm on the Continent and had huge influence among broad elements of the American intelligentsia. What is left of Marx? Not as a governing ideology, but as a work of social science that still has validity? Virtually nothing.