Yes, it's awful to explicate this line, whose dazzling brilliance does discourage close scrutiny. But lest Pound be accused of incoherence,I'd suggest that a meaning is extractable. The "dragon world" is the puny ant'sworld of mythic illusion, and within it he has the power and wisdom of a Centaur -- powerful and wise creatures, one of whom was the teacherof Aesculapius."Vanity" is a logical theme to follow -- more logical than most of the Cantos' links.