Pico della Mirandola discusses the interrelations between these three worlds in the introduction to his Heptaplus: 'For euen as the...three worlds being girt and buckled with the bands of concord doe by reciprocall libertie, interchange their natures; the like do they also by their appellations. And this is the principle from whence springeth & groweth the discipline of allegoricall sense' (translated by Pierre de la Primaudaye in The French Academie, London, 1618, p. 671).