Aquinas and Clarke's Views on Cosmological Argument for God's Existence, Lecture notes of Reasoning

Download Aquinas and Clarke's Views on Cosmological Argument for God's Existence and more Lecture notes Reasoning in PDF only on Docsity! Cosmological Arguments Arguments that God exists: Review • Ontological: the existence of God follows from the very concept of God. – exp: Anselm’s Ontological Argument • This is the only a priori argument for the existence of God. • Cosmological: The existence of God is posited to explain the existence of (change in) the world. – exp: Aquinas and Clarke – This is an a posteriori argument, in that it relies on something we know only from sense experience—namely, that there is change in the world. Aquinas’ First Cause From The Five Ways St. Thomas Aquinas 1225-1274 Aquinas’s Second Way: • 1. Some things are caused to exist. – And causes precede their effects. • 2. Nothing can cause itself to exist. (If so, it would have to “precede itself.”) • 3. This cannot go on to infinity. – (His argument for this is on the next slide.) • So, there must be a first cause—an uncaused causer. “This cannot go on to infinity.” “Such a series of [prior] causes must however stop somewhere…. Now if you eliminate a cause, you also eliminate its effects, so that you cannot have a last cause [or “last effect”] … unless you have a first. Given therefore … no first cause, there would be no intermediate causes either, and no last effect.” –  i.e., without a first cause, nothing else would have happened, and so nothing would be happening now. –  But things are happening now. –  So, the series cannot go on to infinity. Past Infinity • If the series of previous causes goes backwards infinitely in time, – Then every cause is preceded by a previous cause, which is in turn preceded by a previous cause, etc. to infinity. – In this case, there is no such thing as a “first cause,” as every event has a previous cause. – So, if the universe has an infinitely long past history, there is a cause for everything, and yet there is no first cause to “eliminate.” – Things would be happening now without a first cause , because the series of prior causes would extend infinitely into the past. “Begging the Question” • An argument “begs the question” when it implicitly assumes the very point it is trying to prove. – An argument that begs the question is still valid—i.e., if the premises are true, the conclusion must also be true. After all, the “conclusion” is one of the premises. – But such arguments don’t prove anything, since the “conclusion” is simply assumed to be true. – Can you see where Aquinas begs the question? Aquinas Begs the Question • Aquinas is trying to prove that there must be a “first cause.” – He argues there must be a first cause because otherwise the series of causes would to on to infinity. – He argues the series of causes cannot go on to infinity because then there would be no first cause. • This amounts to arguing that there must be a first cause because otherwise there wouldn’t be first cause. “A Modern Formulation of the Cosmological Argument” Samuel Clarke 1675-1729 Clarke’s Cosmological Argument •  Aquinas didn’t seriously consider the possibility that the universe might have had an infinitely long past history. –  Whether or not it could have is the “question” he “begged.” •  Clarke says that even if the universe has existed for eternity, we still need to posit the existence of God to explain the existence of the entire infinite series of causes and effects—that is, of the universe as a whole. Clarke’s Cosmological Argument: •  1. Suppose (for reductio) that everything there is is part of an infinite series of dependent things –  (where each and every thing is dependent for its existence upon the existence of some previous thing, ad infinitum.) –  that is, suppose that nothing (nothing outside the natural world) caused the world. Clarke’s Cosmological Argument “´ c Æ” means causes “∞” means infinity “D-n” means Dependent Event An infinite series of dependent events: What caused it? ∞ .... ´ c Æ D-3´ c Æ D-2´ cÆ D-1´cÆ Now0 Clarke’s Cosmological Argument: •  4. So the whole series is without any cause. •  5. But this cannot be, and so we must posit the existence of God to explain the existence of this infinite series. Question: •  But why must “the series as a whole” –  that is, a series of past events, where each is caused by a previous past event, which is in turn caused by a previous past event, and so on to infinity- have a cause or explanation? •  Can we (must we) explain everything? The Principle of Sufficient Reason (PSR) •  Everything has a cause or explanation. – This is a deep principle of explanation. It doesn’t say that we can always know what the cause or explanation of something is, but only that everything has some cause or explanation. •  So, nothing “just happens.” •  The (true) answer to “Why?” is never “Just because.” Principle of Sufficient Reason Weak vs. Strong •  Weak Version: There must be a cause or explanation for the existence of every individual thing and event. •  Strong Version: There must be a cause or explanation for the existence of every truth or fact. Weak or Strong? •  Aquinas appeals only to the weak version of the PSR. – That is, he requires only that every individual thing must have a cause. •  Clarke needs the strong version of the PSR. – He thinks we must explain not just every individual event, but why there are any events at all.