The Good

In Plato's Republic the Good is the highest object of knowledge and the goal of the philosopher's education. Socrates declines to say directly what it is, offering instead three great images. In the simile of the sun, the Good stands to the intelligible world as the sun to the visible: as the sun gives both the light by which we see and the growth by which things live, so the Good gives both the truth that makes things knowable and the very being of what is known.

It is in this context that Socrates makes his most startling claim — that the Good is itself 'beyond being', surpassing it in dignity and power — words that the later tradition would seize upon. The simile is followed by the divided line and the allegory of the cave, which chart the ascent toward it.

The Good is what every soul pursues, even when it mistakes the object of its longing; nothing is worth having without it, and the vision of it transforms the one who attains it. To govern well, Plato holds, one must first have seen the Good and then be willing to return to the shadows and rule.

The Neoplatonists identified the Good with the One, reading Plato's 'beyond being' as the charter for a first principle above all thought and existence — the source toward which the whole of reality is drawn back in desire.

Sun, Line, and Cave

In the Republic Plato approaches the Good through three linked images. The Sun makes the Good the cause of both being and knowing, as the sun gives both growth and light. The Divided Line ranks the modes of cognition that climb toward it. The Cave dramatizes the soul's painful ascent from shadows to the source of all light — and the duty to return and free others.