Allegory of the Cave
The Allegory of the Cave primarily depicts Plato's distinction between the world of appearances and the 'real' world of the Forms, as well as helping to justify the philosopher's place in society as king. Plato imagines a group of people who have lived their entire lives as prisoners, chained to the wall of a cave in the subterranean so they are unable to see the outside world behind them. However a constant flame illuminates various moving objects outside, which are silhouetted on the wall of the cave visible to the prisoners. These prisoners, through having no other experience of reality, ascribe forms to these shadows such as either "dog" or "cat".