What does it take for a Princeton professor of philosophy to hit the New York Times’ best-seller lists and score an appearance on The Daily Show with Jon Stewart? A short essay on bullshit. This little book comes in under 70 pages and takes about three-quarters of an hour to read carefully, but it’s a serious look at what qualifies as bullshit in both the philosophical and the linguistic senses. It’s not a joke, folks; Frankfurt is taking a look at the difference between bullshitting and lying, both in terms of intent and action. What makes bullshit less threatening and more forgivable than other forms of deception? How does bullshit compare with humbug? Why is a bull session different from a hen session? Frankfurt knows, and he’s telling. Who knew philosophy could be so entertaining?