Aquinas' First Cause Argument: Understanding God's Role in the Universe, Lecture notes of History

Download Aquinas' First Cause Argument: Understanding God's Role in the Universe and more Lecture notes History in PDF only on Docsity! THE Bie) a) Ror Neis 3 WE ji Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument Our first topic is the question of whether God exists. But what does it mean to say that God exists? Don’t people have different ideas of what God could be? In this class, we’ll be working with the conception of God common to what are often thought of as the major monotheistic religions — Christianity, Judaism, and Islam. Here is the view of God common to these religions: The classical conception of God God is not part of the universe, but is the creator of the universe. God is also all-powerful, all-knowing, and perfectly good. God has always existed, and always will exist. God is the greatest being that could exist. THE FIRST Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument Many arguments for God’s existence are best thought of as arguments against simple atheism. Whether they also amount to good arguments for the existence of God then depends in part on how seriously you take quasi-theism. This is something to which we will return. Let’s turn then to our first argument for the existence of God: the first cause argument we find in the reading from Thomas Aquinas. St. Thomas was born in 1225 and, while his works were extremely controversial in their time — some were condemned as heretical by the bishop of Paris — he has since come to be regarded as the greatest theologian and philosopher in the history of the Church. His Summa Theologiae — from which the arguments we will be discussing were taken — is regarded by many as the definitive philosophical exposition of the Catholic faith. Let’s turn then to our first argument for the existence of God: the first cause argument we find in the reading from Thomas Aquinas. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument The second way is from the nature of efficient cause. In the world of sensible things we find there is an order of efficient causes. There is no case known (neither, indeed, is it possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause … Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate, cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first cause, to which everyone gives the name of God. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument Let’s start with the second sentence. Our goal is to come up with a simple, straightforward way to state the main point of this sentence. We always want to use language which is as simple and clear as possible. There are some causes. The second way is from the nature of efficient cause. In the world of sensible things we find there is an order of efficient causes. There is no case known (neither, indeed, is it possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause … Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate, cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first cause, to which everyone gives the name of God. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument Let’s have a look at the next sentence. How would you state this claim in simple language? There are some causes. Nothing is the cause of itself. The second way is from the nature of efficient cause. In the world of sensible things we find there is an order of efficient causes. There is no case known (neither, indeed, is it possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause … Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate, cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first cause, to which everyone gives the name of God. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument There are some causes. Nothing is the cause of itself. There are two kinds of premises in arguments: independent premises, which are supposed to stand on their own, and derived premises, which are supposed to follow from other premises. Which do you think this is? The second way is from the nature of efficient cause. In the world of sensible things we find there is an order of efficient causes. There is no case known (neither, indeed, is it possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause … Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate, cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first cause, to which everyone gives the name of God. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument There are some causes. Nothing is the cause of itself. If something were the cause of itself, it would be prior to itself. Nothing is prior to itself. We get one more premise in the next sentence. There are no infinite causal chains. The second way is from the nature of efficient cause. In the world of sensible things we find there is an order of efficient causes. There is no case known (neither, indeed, is it possible) in which a thing is found to be the efficient cause of itself; for so it would be prior to itself, which is impossible. Now in efficient causes it is not possible to go on to infinity, because in all efficient causes following in order, the first is the cause of the intermediate cause, and the intermediate is the cause of the ultimate cause … Now to take away the cause is to take away the effect. Therefore, if there be no first cause among efficient causes, there will be no ultimate, nor any intermediate, cause. But if in efficient causes it is possible to go on to infinity, there will be no first efficient cause, neither will there be an ultimate effect, nor any intermediate efficient causes; all of which is plainly false. Therefore it is necessary to admit a first cause, to which everyone gives the name of God. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument There are some causes. Nothing is the cause of itself. If something were the cause of itself, it would be prior to itself. Nothing is prior to itself. There are no infinite causal chains. It is pretty clear that this is a derived premise, since we get a long argument for it in the passage immediately following. Let’s set this difficult passage to the side for now, and see if we can figure out the shape of Aquinas’ argument. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument There are some causes. Nothing is the cause of itself. If something were the cause of itself, it would be prior to itself. Nothing is prior to itself. There are no infinite causal chains. We’ve now got some premises on the table. But to figure out whether they make for a valid argument, we need to first figure out what conclusion they are supposed to be an argument for. Fortunately, it is pretty clear that at least one thing Aquinas is arguing for is the following: There is a first cause. By this Aquinas means “there is something which causes other things to exist but was not itself caused to exist by anything.” 1. If something were the cause of itself, it would be prior to itself. 2. Nothing is prior to itself. 3. Nothing is the cause of itself. (1,2) 4. There are no infinite causal chains. 5. At least one thing has a cause. 6. Every causal chain must be (i) circular, (ii) infinite, or (iii) have a first cause. ———————————————————————————————————— C. There is a first cause. (3,4,5,6) Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument 1. If something were the cause of itself, it would be prior to itself. 2. Nothing is prior to itself. 3. Nothing is the cause of itself. (1,2) 4. There are no infinite causal chains. 5. At least one thing has a cause. 6. Every causal chain must be (i) circular, (ii) infinite, or (iii) have a first cause. ———————————————————————— C. There is a first cause. (3,4,5,6) A B C E D Here’s an example of a causal chain which seems to show that our argument is invalid. Nothing is the cause of itself, so (3) is true; the chain is not infinite, so (4) is true; there is at least one cause, so (5) is true; the chain is circular, so (6) is true; and yet there is no uncaused cause, so the conclusion is false. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument 1. If something were the cause of itself, it would be prior to itself. 2. Nothing is prior to itself. 3. Nothing is the cause of itself. (1,2) 4. There are no infinite causal chains. 5. At least one thing has a cause. 6. Every causal chain must be (i) circular, (ii) infinite, or (iii) have a first cause. ———————————————————————— C. There is a first cause. (3,4,5,6) This is a little tricky. There is a sense in which in this example nothing is the cause of itself, because nothing is directly the cause of itself. But it still seems like things are indirectly the cause of themselves. After all, if A causes B and B causes C, isn’t there also a sense in which A causes C? Let’s agree to understand “causes” in our argument as meaning “directly or indirectly causes.” Then the kind of causal chain pictured above is ruled out by premise (3). Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument A B C E D 1. If something were the cause of itself, it would be prior to itself. 2. Nothing is prior to itself. 3. Nothing is the cause of itself. (1,2) 4. There are no infinite causal chains. 5. At least one thing has a cause. 6. Every causal chain must be (i) circular, (ii) infinite, or (iii) have a first cause. 7. There is a first cause. (3,4,5,6) 8. If there is a first cause, then God exists. --------------------- C. God exists. AQUINAS’ FIRST CAUSE ARGUMENT Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument But who cares whether this is a valid argument for the conclusion that God exists? What we care about is whether the conclusion is true - and to be sure of that, we need to know that the argument is sound. Validity is only half the puzzle; the premises also have to be true. This argument is valid, and seems to be a plausible interpretation of the piece of text we’ve been looking at. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument 1. If something were the cause of itself, it would be prior to itself. 2. Nothing is prior to itself. 3. Nothing is the cause of itself. (1,2) 4. There are no infinite causal chains. 5. At least one thing has a cause. 6. Every causal chain must be (i) circular, (ii) infinite, or (iii) have a first cause. 7. There is a first cause. (3,4,5,6) 8. If there is a first cause, then God exists. --------------------- C. God exists. AQUINAS’ FIRST CAUSE ARGUMENT Suppose that someone objected to the argument by saying that, while it is valid, it has a single false premise — premise (7). Why would this be confused? So to defend Aquinas’ argument, we just need to defend its independent premises — (1), (2), (4), (5), (6), and (8). Which of these look the most questionable? Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument I suggest that we focus in on premises (4) and (8). 8. If there is a first cause, then God exists. 4. There are no infinite causal chains. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument But even if Aquinas’ defense of (4) is unsuccessful, (4) might still be true. When you encounter an argument in which one of the premises is insufficiently well defended by the author, you should always ask: can we do better? 4. There are no infinite causal chains. One attempt to do better begins with the thought that just because certain mathematical notions make sense, it does not automatically follow that every real world scenario involving those notions makes sense. For example, the idea of negative numbers makes sense. But would it make sense for me to say that I have -16 apples in my refrigerator? Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument For example, the idea of negative numbers makes sense. But would it make sense for me to say that I have -16 apples in my refrigerator? One might then try to make a parallel argument about infinity. Perhaps the idea of an infinite series of numbers makes sense, but the idea of an infinite causal chain does not. One way to argue for this is to argue that, more generally, the idea of an infinite collection of things existing in space and time does not make sense. Let’s consider some curious features of infinite collections. Consider the collection of natural numbers 1, 2, 3, 4, 5, 6, …. And compare this to the collection of even natural numbers 2, 4, 6, 8, ... Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument Let’s consider some curious features of infinite collections. Consider the collection of natural numbers 1, 2, 3, 4, 5, 6, …. And compare this to the collection of even natural numbers 2, 4, 6, 8, ... Which collection is bigger? It is very natural to say: the collection of all of the natural numbers is bigger. After all, it contains everything in the collection of even numbers, and a bunch more things besides (namely, all of the odd numbers). But this is incorrect: the two collections are of exactly the same size. To see this, note that we can match up the two collections, so that every member of one collection is paired with a member of the other collection. 1 is paired with 2, 2 with 4, 3 with 6, etc. We never run out of even numbers! Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument collection is bigger?not be an infinite collection of real-world things, like books. But an infinite causal chain would be just such an infinite collection. So, the argument concludes, the idea of an infinite causal chain — just like the idea of an infinite library — makes no sense, and there could not be such a thing. How might the believer in infinite causal chains reply? They might just say: infinite collections are just weird, but not impossible. But they might also argue that most theists are already committed to the possibility of infinite causal chains. Isn’t the afterlife supposed to be never-ending? And wouldn’t that mean that there is an infinite causal chain? True, it would be infinite in the ‘forward’ direction’ rather than the ‘backward’ direction — but why should that matter? Here the theist might reply that even if the afterlife is never-ending, there is no point in the the afterlife at which there will have been an infinite series of causes. (Analogously, if you count up the natural numbers, you never get to an infinite number.) Whether this is a good reply is something you might want to think more about. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument Let’s turn to premise (8). Here is one hypothesis which would seem to falsify (8): 8. If there is a first cause, then God exists. This would appear to be a description of a world in which there is a first cause, but God does not exist. And it appears to be entirely consistent with simple atheism. So it looks as though, if we are to believe (8), we must have some reason for rejecting the above hypothesis. The Big Bang The first event in the history of the universe was an explosion of an extremely dense collection of particles, with every particle moving apart from every other particle. This event had no cause - in particular, no being set it into motion - and, further, every subsequent event has been an effect of this event. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument Might one defend (8) by saying that this hypothesis is impossible, on the grounds that there can’t be an uncaused cause? Instead, it seems like a defender of the first cause argument has to argue that nothing like the Big Bang could genuinely be a first cause. Things like the Big Bang have to have a cause; but things like God don’t. But why? This would appear to be a description of a world in which there is a first cause, but God does not exist. And it appears to be entirely consistent with simple atheism. So it looks as though, if we are to believe (8), we must have some reason for rejecting the above hypothesis. The Big Bang The first event in the history of the universe was an explosion of an extremely dense collection of particles, with every particle moving apart from every other particle. This event had no cause - in particular, no being set it into motion - and, further, every subsequent event has been an effect of this event. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument How might we lay out this argument? Everything which begins to exist at some time must have a cause. There is a first cause. There is a first cause which had no beginning. The universe and everything in it began to exist at some time. There is a beginningless first cause of the universe and everything in it. If there is a beginningless first cause of the universe and everything in it, then God exists. God exists. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument We can put this together with the argument from Aquinas to give us the following kalām argument (named after the school of Islamic thinkers who developed several versions of it). THE KALĀM FIRST CAUSE ARGUMENT [premises 1-6 are the same as in Aquinas’ first cause argument] ... 7. There is a first cause. (3,4,5,6) 8. Everything which begins to exist at some time must have a cause. 9. There is a first cause which had no beginning. (7,8) 10. The universe and everything in it began to exist at some time. 11. There is a beginningless first cause of the universe and everything in it. (9,10) 12. If there is a beginningless first cause of the universe and everything in it, then God exists. ———————————————————————————————————— C. God exists. (11,12) Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument There are a number of questions one could raise about this argument. But let’s focus in on one premise: 12. If there is an eternally existing first cause of the universe and everything in it, then God exists. Could one object to this premise in much the way that we objected to Aquinas’ assumption that if there is a first cause, then that thing must be God? How do we know that this beginningless thing which is outside of the universe and caused the universe to exist is God? This is a reasonable question. Here is one way which a defender of the kalām argument might respond. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument which we began. quasi-theists that God exists. But that does not mean that the argument should not convince many people that it is much more likely that God exists than they thought it was before encountering the argument. 90% Here an analogy might help. Consider the question of whether Santa Claus exists. Santa Claus is meant to be a bearded jolly elf who is thousands of years old who lives at the North Pole and delivers toys to children all around the world with the help of his flying reindeer. We can distinguish three different views on the Santa question. First, there is the belief that Santa exists. Second, there is Santa-skepticism: the belief that nothing exists with any of the properties ascribed to Santa. Third, there is quasi-Santa-ism: the view that something lives at the North Pole with some of the properties traditionally ascribed to Santa, but not all. Suppose that you are a Santa-skeptic. But suppose now that you encountered a surprisingly convincing argument for the existence of an ancient jolly elf living at the North Pole who has in fact been delivering toys all around the world for centuries. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument which we began. quasi-theists that God exists. We can distinguish three different views on the Santa question. First, there is the belief that Santa exists. Second, there is Santa-skepticism: the belief that nothing exists with any of the properties ascribed to Santa. Third, there is quasi-Santa-ism: the view that something lives at the North Pole with some of the properties traditionally ascribed to Santa, but not all. Suppose that you are a Santa-skeptic. But suppose now that you encountered a surprisingly convincing argument for the existence of an ancient jolly elf living at the North Pole who has in fact been delivering toys all around the world for centuries. Would it be reasonably for you to respond to the argument by saying: “OK, I now have to admit that Santa-skepticism is false. But I still don’t believe that Santa exists. You haven’t, after all, shown me that the elf is bearded, or that he has flying reindeer! I therefore adopt quasi-Santa-ism.” It is at least arguable that this would not be very reasonable. Just who is this elf supposed to be, if not Santa? Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument which we began. quasi-theists that God exists. One might make a parallel point about the quasi-theist response to the kalam argument. 90% Just to have an example, let’s imagine that you are an agnostic, and that you think that simple theism has a 45% chance of being true, simple atheism has a 50% chance of being true, and quasi-theism has a 5% chance of being true. Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument which we began. quasi-theists that God exists. SIMPLE THEISM SIMPLE ATHEISM But if you eliminate simple atheism from the picture, you have to adjust the probabilities you assign to simple theism and quasi-theism. After all, you know that one of these two theories is true -- so the probabilities you assign to them should add up to 100%. 0% 90% 45% Before encountering the kalām argument, you thought (in this example) that simple theism was 9 times more likely to be true than quasi-theism. Nothing in that argument seems to affect this view; so it looks like you should keep it. 10% 5% QUASI- THEISM Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument which we began. quasi-theists that God exists. 90% SIMPLE THEISM SIMPLE ATHEISM 0% Before encountering the kalām argument, you thought (in this example) that simple theism was 9 times more likely to be true than quasi-theism. Nothing in that argument seems to affect this view; so it looks like you should keep it. 10% The result (in this example) is that you should now think that simple theism has a 90% chance of being true. QUASI- THEISM Three views about the universe Aquinas’ first cause argument Two objections to Aquinas the kalām argument which we began. quasi-theists that God exists. The result (in this example) is that you should now think that simple theism has a 90% chance of being true. This is just one example. But it illustrates how an argument might (very) substantially increase the probability you assign to its conclusion even if it does not definitively rule out every other possibility.