  To avoid the problem that she identifies with Descartes and Hobbes, Conway asserts a monism: all creatures are composed of one kind of substance—spiritual. To avoid the problem she associates with Spinoza, Conway asserts that while only one (spiritual) substance exists, the universe is divided into three “species” that differ in their essences: creatures, Christ, and God. This tripartite separation is grounded on the basis of the changeability of the member(s) of the species: the essential feature of creatures is that they can change for the better and for the worse, the essential feature of Christ is that he can only change for the better, and God’s essence is that He is unchanging (Chapter VI, section 4). In postulating these three “species” of the one substance, Conway is able to assert God’s separation from creation, as well as a metaphysically and morally mediating role for Christ. This mediating role for Christ is of central importance to Conway’s theodicy. On her view, accepting this tripartite division of species “will contribute greatly to the propagation of the true faith and Christian religion among Jews and Turks and other infidel nations” (Chapter VI, section 5). This is because once we appreciate the reasoning in favor of a mediator between creatures and God, and we accept this reasoning, we believe in Christ whether we call the mediator by that name or not. In this way, Conway can answer a particularly difficult challenge to any Christian thinker: how can Christianity be the universal religion, in which salvation depends on knowing Christ, when so much of the Earth’s population is ignorant of Christ? On her system, she can assert that many people may know Christ as mediator, without knowing him by name or even by role in the Christian religion.