Lord, teach us to take our hearts and look them in the face, however difficult it may be.
—Gaudy Night (1935)

Might as well admit it: once upon a time, disinclined to mix business with pleasure, I found the very idea of the “Philosophical Novel” off-putting. It was Alison Lurie’s Imaginary Friends, a deliciously comic exploration of cognitive dissonance and of the pitfalls of social-scientific inquiry, that changed my mind and persuaded me of the merits of mixing pleasure with business. I began to appreciate how a work of fiction may explore philosophical questions and— by means of statements which, being about fictional characters, are not true—convey philosophical truths; and I soon began to acquire a taste for (not the epistolary but) the epistemological novel.

In this genre, I have a particular admiration for Samuel Butler’s reflections on the ubiquitous epistemological vices—self-deception, sham inquiry, hypocrisy—that really are The Way of All Flesh, and an especial fondness for Dorothy L. Sayers’s Gaudy Night, a book I discovered only when a graduate student who had heard me give a lecture entitled “Concern for Truth: What It Means, Why It Matters” sent me a copy. She was right on the mark. For the plot of Sayers’s story turns precisely on a character’s concern for truth and the disastrous series of reactions it prompts, and an important preoccupation is the relation of epistemological to other values: why is honesty valuable in scientific and other inquiry? Is suppressing