The soul is like a perfect sphere, as Empedocles described it. It keeps its natural shape when it doesn't reach out greedily for things or shrink back in fear. When the soul stays whole like this, it shines with its own light. In that light, it can see clearly — both the true nature of the world and its own true nature.
Then is the soul as Empedocles doth liken it, like unto a sphere or globe, when she is all of one form and figure: when she neither greedily stretcheth out herself unto anything, nor basely contracts herself, or lies flat and dejected; but shineth all with light, whereby she does see and behold the true nature, both that of the universe, and her own in particular.