Philosophers make a distinction between two kinds of evils according as each kind has a different cause. At the very least, we should recognize, as Richard Lewontin did in the passage quoted above, that to claim that only materialist explanations of reality are acceptable is a philosophical assumption not required by the "methods and institutions of science. Aquinas distinguishes between necessary things which have a cause of their necessity and God who is necessary in Himself. . "[4] To affirm a fundamental continuity among living things challenges the notion that distinct species were created by God through special interventions in nature. A master principle which informs Aquinas' analysis of creation is that the truths of science cannot contradict the truths of faith. Evolution and creation take on cultural connotations, serve as ideological markers, with the result that each comes to stand for a competing world-view. Traditionally, the Big Bang has been seen as a singularity at which the laws of physics break down. Aquinas does not think that God "allows" or "permits" creatures to behave the way they do. [10]Too often, however, these perceived challenges are the result of fundamental confusions. To understand how the thought of Aquinas is important for contemporary discourse on creation and evolution we need to return, however briefly, to the intellectual world of the Latin Middle Ages. He remained there until 1252, when he returned to Paris to prepare for the degree of master of theology. Thus, they would say that when fire is burning a piece of paper it is really God who is the true agent of the burning; the fire is but an instrument. Therefore, evil, which is universally contrary to good, is necessarily also contrary to existing. Of all of Darwin's proposals, the one his contemporaries found most difficult to accept was the theory of common descent applied to Man. Ernst Mayr, "Darwin's Influence on Modern Thought,". Both Albert the Great and Bonaventure argued, contrary to the view of Aquinas, that to be created necessarily means to have being after non-being. Since natural or physical evil is real and objective, and since evil is the privation of goodness due to a thing according to its nature, the natures of things have to be real and objective as well, in order for things to suffer these natural evils. In 1277 the Bishop of Paris, Étienne Tempier, issued a list of propositions condemned as heretical, among them the claim that the world is eternal. Stoeger points out that the natural sciences discover an order and directedness inherent in physical reality: "in the laws, regularities, and evolving conditions as they function together to constitute the processes and relationships which emerge at each stage of cosmic history." The complete dependence of the creature on the Creator means that there is a kind of priority of non-being to being in any creature, but this priority is not fundamentally temporal. Although "chance events are frequent and important in biological evolution, rendering its actual course indeterminate or unpredictable in exact outcome from any particular stage, these events and their short- and long-term effects whether they be of point mutations at the level of molecular DNA, or the impact of a meteorite are always within a context of regularities, constraints, and possibilities." Aquinas and others in the Middle Ages would have found strange indeed Darwinian arguments of common descent by natural selection. . . Although Aquinas does not think that one can use reason alone to conclude that the universe is temporally finite and thus know, on this basis, that it is created out of nothing, he does think, as we have seen, that in the discipline of metaphysics one can know that the universe is created.