1. Is Belief in God Reasonable? Faith Seeking Understanding A posteriori arguments (based on experience): The teleological argument (from design) The cosmological argument A priori argument (independent of experience): The ontological argument

2. The Cosmological Argument: St. Thomas Aquinas u Like all things in it, the universe is contingent (it depends on something else for its existence); otherwise, its existence is unintelligible u If there is no cause of the universe right now (that is, if its cause is infinitely remote), then nothing would exist right now. But things do exist here and now, so God exists here and now (1225-74)

3. Hume’s Criticisms of the Cosmological Argument u No being (including God) exists necessarily u If God is eternal, why not the universe too? u Fallacy of composition: parts  whole u Why think everything has a cause or reason? u Besides, the argument does not prove that God is anything other than a cause of things who might not care at all about his creation

4. The Ontological Argument: St. Anselm P1: “God” means the greatest conceivable being P2a: A being that exists in one’s mind and in reality (outside of one’s mind) is greater than one that exists only in one’s mind P2b: A necessarily existing being is greater than a merely possible being u Therefore, God must exist in reality (1033-1109)

5. Objections to Anselm’s Argument u Gaunilo: imagining anything as perfect does not make it exist –Reply: the non-existence of everything other than God is conceivable u Immanuel Kant: to say that God exists does not say anything about God: his existence is not one of his properties. To deny that God exists does not address what he is, only that he is –Reply: the (non)-existence of some things (e.g., unicorns) is part of their definition (1724-1804) Kant