In the following essay, Wilson criticizes some of the conclusions presented in Freakonomics, and contends that its strength lies with the questions it asks, rather than the answers it offers.

During my many years of lecturing on crime, invariably the first two questions I would be asked were: "What do you think of the death penalty?" and "What do you think of gun control?"

No more. Now the first question is whether I believe that legalized abortion has cut the crime rate. For this I can thank Freakonomics, the weirdly named book by Steven D. Levitt and Stephen J. Dubner that has been high on the New York Times best-seller list for weeks now. My answer, by the way, is no: I do not believe the evidence shows a causal link between legalized abortion and our reduced crime rate.

Levitt, an acquaintance of mine, is a immensely...