Concerning the Nature of Good, Against the Manichaeans

Therefore a bad measure, a bad form, a bad order, are either so called because they are less than they should be, or because they are not adapted to those things to which they should be adapted; so that they may be called bad as being alien and incongruous; as if any one should be said not to have done in a good measure because he has done less than he ought, or because he has done in such a thing as he ought not to have done, or more than was fitting, or not conveniently; so that the very fact of that being reprehended which is done in a bad measure, is justly reprehended for no other cause than that the measure is not there maintained.

Likewise a form is called bad either in comparison with something more handsome or more beautiful, this form being less, that greater, not in size but in comeliness; or because it is out of harmony with the thing to which it is applied, so that it seems alien and unsuitable. As if a man should walk forth into a public place naked, which nakedness does not offend if seen in a bath. Likewise also order is called bad when order itself is maintained in an inferior degree. Hence not order, but rather disorder, is bad; since either the ordering is less than it should be, or not as it should be. Yet where there is any measure, any form, any order, there is some good and some nature; but where there is no measure, no form, no order, there is no good, no nature.