Trinity at the beginning of his Church Dogmatics, including a subscription to the inseparability rule together with the attendant corollary of appropriation. Others, like Wolfhart Pannenberg and Jürgen Moltmann, give reformulations of the doctrine. On the Catholic side, Karl Rahner introduces certain amendments to it. Throughout contemporary Trinitarian conversations, however, the universal applicability of the rule is being challenged. At this stage it is helpful to understand what the objections