Everything that depends on the action of nature is by nature as good as it can be, and similarly everything that depends on art or any rational cause, and especially if it depends on the best of all causes.
If goodness has causes, it is not goodness; if it has effects, a reward, it is not goodness either. So goodness is outside the chain of cause and effect.
Those which are produced from causes are not produced. they do not have an inherent nature of production. those which depend on causes are said to be empty; those who know emptiness are aware.