'Vain is the word of that philosopher which does not heal any suffering of man." By the lights of this maxim, taken from the fourth-century B.C. Greek philosopher Epicurus, contemporary philosophy looks awfully vain. Upon opening the field's most prestigious journal, one finds little that looks capable of healing and much that promises the opposite: an article titled "On the Supposed Inconceivability of Absent Qualia Functional Duplicates"; another that defends the "applicability of Bayesian confirmation theory to the Everett interpretation of quantum mechanics." Epicurus, by contrast, taught...