Plato's Cave, after Cornelis van Haarlem

This print illustrates the best known passage and the most useful metaphor for the theory of Forms in Plato’s Republic. In the depths of a cave, statuettes are illuminated by a lantern and cast shadows upon a wall. On the right, huddled in the darkness, most of humanity mistakes these shadows for reality, without understanding that they are dim representations twice removed. On the left, philosophers discuss the nature of the light and shadows – reality at the next level – without grasping that it too is only a representation. Finally, just outside the cave, a few figures stand in daylight, the actual reality of the immaterial and eternal Forms. The Steinberg Collection counts 18 engravings by Saenredam, the subtlest of Goltzius’s followers. This is one of the most striking and rare.