Vlastimil Vohánka (2013) argues that van Inwagen has done nothing to show the logical possibility of any Trinity theory. Just because a set of claims can’t be proven inconsistent in van Inwagen’s relative identity logic, it doesn’t follow that such claims don’t imply a contradiction, or that it is metaphysically possible that all the claims are true. At one point van Inwagen tells a short non-theological story whose claims, when translated into his relative identity logic, have the same forms as the Trinity propositions. The story, he argues, is clearly not self-contradictory; thus, he conclud...