  This allows, then, that in the two major paradigms of such causation—in natural generation and in artificial production—the forms—the nature of the natural entity, and the  art[31]  of the craftsman exercising his art respectively—are the causally operative entities initiating change. This has wide ranging consequences for the status of forms in several respects. First, the causal relevance of these forms shows that not any arrangement or configuration can qualify as a full-fledged form. While it is true that privations are also forms in some sense (Physics 2.1, 193b19–20), this is not the sense in which the causally operative forms, describable in evaluative terms, can be called forms. Moreover, the causal relevance of forms allows Aristotle to switch (e.g. in De generatione et corruptione 1.7) without notice between the craftsman and the craft itself as the appropriate specification of the efficient cause in these cases. We should note that in the latter cases, Aristotle specifies causes which are unmoved. They do not effect motion by being in motion themselves, in so far as they are the causally effective forms within the causal framework; hence they are not under any reactive influence during this process either.