A few weeks ago, I gave a talk at the American Philosophical Association, in an excellent, serious symposium on human experience and rationality. The only problem was that my appearance meant missing the brilliant, addictive TV series “The Americans.” Thank heavens for on-demand cable—otherwise the temptation to skip the conference and catch up on the latest betrayals and deceptions might have been too much for me.

Still, one practical benefit of a philosophical education is that it helps you to construct elaborate justifications...