The enigmatic, fantastically erudite artist Raymond Pettibon takes to Twitter like a bird to sky. My favorite of some fifty tweets that he posted on a recent day offers a reason that Donald Trump can't be the Antichrist: "Not charming, goodlooking, endearing enuff." In his art, Pettibon only sometimes addresses topical politics, or topical anything, but he knows his archetypes, and it's nice to have eschatological expertise on current events. How seriously to take it is an uncertainty that haunts all of Pettibon's art, which is surveyed in "A Pen of All Work," a retrospective at the New Museum of some seven hundred creations, mostly drawings with text. He has intrigued and befuddled a growing audience since the late nineteen-seventies, when he emerged, in Hermosa Beach, California, as a bookish surfer who made flyers and album covers for the punk band Black Flag (his older brother Greg Ginn was the founder and guitarist) and a flurry of zines. His fame took hold slowly, and it remains confined largely to fine-art circles. Seeing the show is like being lost in a foreign but strangely familiar city, where polyphonic disembodied voices whisper, yell, or sputter wit and wisdom that you're rarely sure that you heard quite right.