We may suffer for it when the balance of things rights itself, but we do not lose hope and forego art and forget the words of the Making. Nature is not unnatural. This is not a righting of the balance, but an upsetting of it. There is only one creature who can do that.
A man? Arren said, tentative.
We men.
How?
By an unmeasured desire for life.
For life? But it isn't wrong to want to live?
No. But when we crave power over life—endless wealth, unassailable safety, immortality—then desire becomes greed. And if knowledge allies itself to that greed, then comes evil. Then the balance of the world is swayed, and ruin weighs heavy in the scale.

Chapter 3, "Hort Town" (Ged and Arren) - Earthsea Books - The Farthest Shore (1972)