Love is the joy of the good, the wonder of the wise, the amazement of the gods; desired by those who have no part in him, and precious to those who have the better part in him.
Each living creature is said to be alive and to be the same individual - as for example someone is said to be the same person from when he is a child until he comes to be an old man. And yet, if he's called the same, that's despite the fact that he's never made up from the same things, but is always being renewed, and losing what he had before, whether it's hair, or flesh, or bones, or blood, in fact the whole body.
The true lover of knowledge naturally strives for truth, and is not content with common opinion, but soars with undimmed and unwearied passion till he grasps the essential nature of things.