T he word “visionary” is done to death but the 17th-century Spanish painter Francisco de Zurbarán demands it: he paints supernatural things naturally and natural things supernaturally. Space becomes different in his world, melting distance and erasing the barrier between you and the picture. The very first painting in this dreamlike ecstasy of a show dissolves logic. A monk robed in white kneels before a living man hanging upside down, his hands and feet nailed to an inverted cross: it’s a vision as real and close to us as it is to the awestruck monk, held in a penumbra of bronze fire, a stream of smoky light from heaven. Huge presence … Colossal Head attributed to Francisco de Zurbarán. Photograph: Baztan José y Aciego de Mendoza/© Photographic Archive Museo Nacional del Prado The Apparition of Saint Peter to Saint Peter Nolasco from 1629 has been lent by the Prado and depicts Nolasco receiving a vision of the original St Peter who asked to be crucified upside down so he would not imitate Christ.…