in the Summa Theologica (I, Q.2, art.3) are five possible ways of demonstrating the existence of God, which today are categorized as: 1. Argumentum ex motu, or the argument of the unmoved mover; 2. Argumentum ex ratione causae efficientis, or the argument of the first cause; 3. Argumentum ex contingentia, or the argument from contingency; 4. Argumentum ex gradu, or the argument from degree; and 5. Argumentum ex fine, or the teleological argument. Despite this, Aquinas also thought that sacred mysteries such as the Trinity could only be obtained through revelation; though these truths cannot contradict reason: Aquinas responds to the problem of evil by saying that God allows evil to exist that good may come of it, (for goodness done out of free will is superior than goodness done from biological imperative) but does not personally cause evil Himself. View of God Aquinas articulated and defended, both as a philosopher and a theologian, the orthodox Christian view of God. God is the sole being whose existence is the same as His essence: "what subsists in God is His existence." (Hence why God names himself "I Am that I Am" in Exodus 3:14.) Consequently, God cannot be a body (that is, He cannot be composed of matter), He cannot have any accidents, and He must be simple (that is, not separated into parts; the Trinity is one substance in three persons). Further, He is goodness itself, perfect, infinite, omnipotent, omniscient, happiness itself, knowledge itself, love itself, omnipresent, immutable, and eternal. Summing up these properties, Aquinas offers the term actus purus (Latin: "pure actuality"). Aquinas held that not only does God have knowledge of everything, but that God has "the most perfect knowledge," and that it is also true to say that God "is" His understanding. Aquinas also understands God as the transcendent cause of the universe, the "first Cause of all things, exceeding all things caused by Him," the source of all creaturely being and the cause of every other cause. Consequently, God's causality is not like the causality of any other causes (all other causes are "secondary causes"), because He is the transcendent source of all being, causing and sustaining every other existing thing at every instant. Consequently, God's causality is never in competition with the causality of creatures; rather, God even causes some things through the causality of creatures. Aquinas was an advocate of the "analogical way", which