The Relationship Between the Active Man and the Quality

How can the thing qualified by equality refer to the quality? This must be studied because the thing qualified and the quality do not belong to a common kind. In this case, would we distinguish several ways of being useful or harmful? Should we then divide the properties of the bodies according to the difference of their effects, or according to their useful or harmless character? Since this character is a property of quality, surely to be useful or harmful seems to be the property of both the quality and the thing qualified. Otherwise we should have to seek some other classification.