Can bad people create good art? If that question pops up on an exam or at a dinner party, you might want to be wary. The obvious answer — so obvious that it practically goes without saying, and ought to make the examinee suspicious — is that bad people, or at least people who think and behave in ways most of us find abhorrent, make good art all the time. Probably the most frequently cited example is Wagner, whose anti-Semitism was such that he once wrote that Jews were by definition incapable of art. Degas, a painter often praised for his warmth and humanity, was also an anti-Semite and a staunch defender of the French court that falsely convicted Alfred Dreyfus. Ezra Pound was both anti-Semitic and proto-fascist, and if you want to let him off the hook because he was probably crazy as well, the same excuse cannot be made for his friend and protégé T. S. Eliot, whose anti-Semitism, it now seems pretty clear, was more than just casual or what passed for commonplace in those days.

Anti-Semitism turns up so often in the résumés of 20th-century artists, in fact, that it almost seems part of the job description, and critics and commentators have sometimes tried to mitigate if not excuse it. Wagner, they point out, had Jewish friends. Eliot was a devout, churchgoing Anglican — surely not a “bad” person in any extreme way. So for now, let’s leave anti-Semitism off the list. How about misogyny, or generally creepy behavior toward women? Picasso probably takes the prize here: of the seven main women in his life, two went mad and two killed themselves. His standing could be in jeopardy, though, if the crime novelist Patricia Cornwell ever succeeds in proving her conviction — argued at length and at great expense in her book Portrait of a Killer: Jack the Ripper— Case Closed — that the British painter Walter Sickert was in fact the famous serial killer.

Speaking of killing, Norman Mailer in a rage once tried to kill one of his wives. The painter Caravaggio and the poet and playwright Ben Jonson both killed men in duels or brawls. Genet was a thief, Rimbaud was a smuggler, Byron committed incest, Flaubert paid for sex with boys. So case closed, one is tempted to say, invoking Ms. Cornwell’s phrase: anti-Semitism, misogyny, racism (I left that out, but there are too many examples to cite), murderousness, theft, sex crimes. That’s not to mention the drunkenness, drug-taking, backstabbing, casual adultery and chronic indebtedness that we know attended (or attends) the lives of so many people who make unquestionably good art. Why should we be surprised or think otherwise? Why should artists be any better than the rest of us?

The reason that question — “Can bad people create good art?” — is misleading is that badness and goodness in this formulation don’t refer to the same thing. In the case of the artist, badness or goodness is a moral quality or judgment; in the case of his art goodness and badness are terms of aesthetic merit, to which morality does not apply. The conductor Daniel Barenboim, a Jew, is a champion of Wagner’s music, for example, and has made a point of playing it in Israel, where it is hardly welcome. His defense is that while Wagner may have been reprehensible, his music is not. Barenboim likes to say that Wagner did not compose a single note that is anti-Semitic. And the disconnect between art and morality goes further than that: not only can a “bad” person write a good novel or paint a good picture, but a good picture or a good novel can depict a very bad thing. Think of Picasso’s Guernica or Nabokov’s Lolita , an exceptionally good novel about the sexual abuse of a minor, described in a way that makes the protagonist seem almost sympathetic.