Allegory of the Cave
In "The Republic", Plato argues that the "real objects of knowledge are not the changing objects of the senses, but the immutable Forms," stating that the "Form of the Good" is the highest object of knowledge. His argument culminates in the Allegory of the Cave, in which he argues that humans are like prisoners in a cave, who can only see shadows of the Real, the "Form of the Good". Humans are to be educated to search for knowledge, by turning away from their bodily desires toward higher contemplation, culminating in an intellectual understanding or apprehension of the Forms, c.q. the "first principles of all knowledge."