The stone of madness

The famous Dutch surrealist Hieronymus Bosch, “the creator of devils,” left behind only a small but genius body of deeply original work crammed with disturbing symbolism. The 25 or so priceless paintings, in a dwindling list definitely attributed to him during the Renaissance are moralistic masterpieces from a magical mind overrun with manic monsters. Nothing is as it first seems, so that in one bizarre 15th century installation the surgeon performing a craniotomy wears a funny funnel hat and makes an incision from which a flower sprouts, watched by a bored woman robed like a nun, but with a book resting on her head.