 Since the goal of practical reason is action not knowledge, the truth attained by the intellect must be caused by its conformity to right desire. There can be no necessary science of practical reason, since virtuous activity allows for variety and derivation from the universal rule in particular instances. Moral matters, which are within the domain of practical reason, are varied and inadequate (deformis), and cannot therefore provide the certainty which is expected in theoretical reasoning. If we are to have any science of practical reason at all, we must be content to apply the principles to various conclusions and proceed from rough arguments which demonstrate truth in a general way.