A sweeping retrospective of Philip Guston’s influential work, from Depression-era muralist to abstract expressionist to tragicomic contemporary masterPhilip Guston—perhaps more than any other figure in recent memory—has given contemporary artists permission to break the rules and paint what, and how, they want. His winding career, embrace of “high” and “low” sources, and constant aesthetic reinvention defy easy categorization, and his 1968 figurative turn is by now one of mod