Thursday, July 31, 2008

Anselm's Proof of God's Existence

Anselm of Cantebury wrote a proof of the existence of God in 1077 that has gotten much attention in the history of western philosophy, partly because of the importance of God in the history of western thought and partly because of the unique qualities of the proof itself. Proofs of God's existence are generally subdivided into various genre's and Anselm's proof is of the "Ontological Argument" type. "Ontology" is the study of Being; so ontological arguments are arguments that directly try to prove that God must exist as a fundamental feature of existence itself.

Anselm meant the argument to convince, but his audience certainly were not those who were unbelievers. The argument was addressed to sophisticated European Christians and for them it served to give reaffirm their belief, not convince. It's never struck me as convincing.

In brief the argument is: God is the greatest thing that one could possibly imagine. It would be even greater for God to exist in reality than in imagination and since God is the greatest thing that one could imagine, God must exist in reality, and not just in imagination. If God only existed in imagination then there could be something greater than God in reality.

I think I would describe the rhetorical force of this argument as its logical confusion. The logical knots that it employs can be intimidating and there is great rhetorical force to intimidation. In fact, explaining the essential fallacy in the argument can itself be quite confusing and may not be as compelling as the argument itself. This is part of the reason it's an enduring and compelling argument.

Let's first look at it very simply. The argument is basically saying that being able to imagine something that can't have anything greater, automatically means, by ontological necessity, that thing must exist. The rest of the argument is just misdirection to conceal this basic assertion.

This assertion gives a lot of power to the imagination. This is basically what Gaunilo of Marmoutiers was trying to show with his example of the island. He basically used the same basic form of the argument to prove that the greatest possible island must exist, on the same grounds that it would be greater for the island to exist in reality than in imagination.

The basic problem with Anselem's argument which we should notice is that there is a big leap from saying something would be greater if it existed in reality rather than imagination to something must exist in reality. If God only existed in imagination then certainly a God that existed in reality would be greater, but just because I can imagine such a God in existence, doesn't mean it automatically must exist in reality in order to satisfy the demands of my imagination. In short, my imagination could be wrong. If I can imagine the greatest thing that is, my imagination could be wrong and my imagination might be exceeding the limits of reality.

I don't know if my counter-argument is as convincing, or if it just muddies the water. Whatever the case may be, I want to treat more of Anselem's argument and it's descendants and I will return to it's appearances again in the history of philosophy, beginning with Descartes.

Monday, July 28, 2008

Vertical & Horizontal Arguments

Since I’ll be spending a lot of time refuting philosophical arguments, it’s useful to make a distinction between two types of arguments. One I will call a vertical argument and the other a horizontal argument. What distinguishes them is their dependency on other parts of the argument, and how easy they are to refute. Let me explain.

Let’s think of the horizontal argument like a chain that is holding up a chandelier hanging from the ceiling. If any link on that chain is weak or breaks, then the chandelier falls. Many an argument is built like that. They are cumulative: each step builds on the previous step. A good example of this would be a mathematical proof, like say Euclid’s proof of the Pythagorean Theorem from Book 1 of the Elements. The argument is built on dozens of steps: a series of definitions, five postulates, forty plus proofs that themselves have several steps to them, and then finally an elaborate argument tying them all together.

Let’s think of the vertical argument like a wall of bricks. The pieces work independently and the more elements, the stronger the argument. For example, an argument in a courtroom. Imagine you’ve got a man you suspect murdered his wife. You have a) a gun at the crime with his fingerprints b) a bullet in her that matches the gun c) a neighbor hearing a gunshot d) someone seeing him drive away shortly after the gunshot and e) an attempt to collect on his wife’s life insurance. Individually, none of these really prove much of anything, but cumulatively you have a pretty airtight case. They don’t depend on each other, so if you knock down one of them, the rest still stand. If you knock down one of them, the overall argument will be weakened but not refuted.

You see, with a horizontal argument, like in the courtroom example, the more individual pieces the stronger the argument. The wall grows stronger and becomes more and more invulnerable even if some holes are poked in it and certain pieces are shown to be fallible. But with a vertical argument the more pieces it has the weaker it is, because it more potentially weak chain links. If you’ve only got three parts to the argument, it’s relatively easy to assure that all three are solid and tempered. But if you’ve got twenty pieces, fallible as we humans are, there’s bound to be a weak step that you’ve included somewhere. This is why it’s a good rule of thumb: the more complex a philosophical argument is the more likely it is to be flawed.

These two aren’t mutually excusive, you could have several vertical arguments supporting a single point, like several chains holding up a chandelier, which gives a much firmer grip, and requires much more to refute.

Vertical argument allow one to construct far more complex ideas, which are more attractive to philosophers and historians of philosophy, and they certainly can be more interesting, but they are more vulnerable and usually represent vast airy spider webs that are swept aside with the wave of a hand.

For my next post I'll look at Anselem's Ontological Argument for God's existence.

Friday, July 25, 2008

Plato’s Phaedo & resurrection of the soul

I discussed the evasiveness of Plato in my previous post as a preface to my discussion of an argument of Plato’s in the Phaedo. Plato tells us that philosophy is a preparation for death (67f). The reason is because the soul persists after death, and the fate of that soul after death is determined by one’s actions in this life, and a philosophical life prepares the soul for the best possible afterlife.

The important argument is how Plato proves the resurrection of the soul. He does this with the argument that everything comes to be from it’s opposite. Day comes from night, something can only become wet from being dry, something can only become large from being small . If everything comes from its opposite, then this means that the living come from the dead (70d), since living is opposite of dead. Thus, when one dies, one goes from the living to the dead, then when is born one must become living from the dead.

If you don’t find this a compelling argument, then you and I are in agreement, but the question is why. The problem is with the definition of opposite. You see, the idea that a thing comes to be from its opposite is a sound argument, if you define opposite in a precise way. You see, when speaking we usually refer to opposites in a very informal way. We might speak of running as the opposite of walking or lying down as the opposite of standing or standing as the opposite sitting. Usually we just mean by opposites two different things within a common category (like human locomotion), which are as different from each other as can be (running and walking). But Plato requires a precise binary opposition for one to say that a thing comes to be from its opposite. If for example we say that there is a transition time between day and night called dawn, then we would say that day comes from dawn, and dawn comes from night. As well, a person needn’t necessarily come to be running from a state of walking, but could’ve been standing still, or lying down, or falling or sitting. If we defined the opposite of running more strictly as “not-running” which includes all states of motion or lack of motion that aren’t running, then we could say that a person comes to be running from a state of non-running. Day comes to be from non-day, dry comes to be from non-dry, etc.

Maybe we might need to define a realm of opposition, that is to say, for example, a hacksaw is non-day, but it would be absurd to say that day comes from a hacksaw. Thus, you’d have to define it so that non-day only includes phases of the diurnal cycle that aren’t part of day, but this is a side issue.

Back to Plato’s argument, the more precise way of putting it is to say that the living come to be from the non-living. When Plato says that the living come from the dead, the implication is that the living come from those not living who were formerly living. But if we are more precise about it, we realize that the realm of non-living includes both those not living who were formerly living and those not living who never were living. In other words, when we are born, the stuff we come from may or may not have been formerly living stuff come from a previous life.

Plato’s argument fails because an unspoken assumption (that the dead only includes those not living who were formerly living) and imprecise definitions (in particular, of what is an “opposite”). Plato exploits the informal nature of our usage of opposite, and he won’t be the last philosopher. Hegel will, two millennia later, use the imprecision of opposition as the backbone of his whole dialectical method, which he uses to describe the movement of spirit and of ideas in general as they progress from opposite to opposite in the constant upward evolution towards absolute being. But that is another matter.

Monday, July 21, 2008

Plato's Evasiveness

Plato can be a sometimes evasive philosopher to treat of. His thoughts are presented in dialogue and never in his own voice, which always leaves the interpreter the option of claiming that any weak argument was made deliberately weak by Plato. This might be giving too much credit to Plato, but there may be some validity to arguments like this.

Plato’s early works are described as aporetic, meaning they are intended to bring one to a state of aporia. This is a Greek word meaning going no further, and a good example of it is in Plato’s dialogue Meno, when Socrates, discussing whether virtue can be taught, leads Meno to a point where he no longer knows how to respond to Socrates questions, and Meno feels like he’s been numbed, as if by a torpedo fish (80a). In other words if you were talking to Socrates, through his leading questions, he would take apart your philosophical reasoning and all subsequent attempts to try and refine your ideas to avoid his critiques, until you felt like you had nothing left to argue. You would feel like all your arguments have been demolished and you don’t know what to think any more. You wouldn’t know how to go any further with your arguments.

This tendency to bring interlocutors to aporia, seems to be something that Plato picked up directly from Socrates. As Plato records Socrates saying in his Apology, when his friend Chaerephon visited the Delphic oracle, it told him that Socrates was the wisest of men, which Socrates could only interpret as himself being the only man aware of his own ignorance. In other words, we humans are all ignorant in comparison to the gods, but we make ourselves even more unwise by thinking that we are not ignorant. As Socrates says: “it is likely that neither of us knows anything worthwhile, but he thinks he knows something when he does not, whereas when I do not know, neither do I think I know”(Grube trans, 21a-e). Socrates thereby makes it his divine mission to expose people to their own ignorance and thereby make them wiser. Thus, this is the relevance of bringing people to a state of aporia. When you have demolished their arguments, they become aware of their own ignorance and thereby become wiser.

Concerning Plato’s dialogues, as I said his early dialogues are described as aporetic, because they are dialogues in which Socrates debates with people and frequently simply undermines their arguments in the course of discussion. Plato’s so called “middle dialogues,” (people aren’t always in agreement exactly which dialogues these are) are usually considered to be presenting positive ideas instead of just critique of other’s ideas. Nonetheless, there might be reason to think they too are aporetic. They not too seldom present multiple strong arguments which disagree, they make allusions to myths and stories, and they have many dramatic elements. And though these dialogues clearly have a central argument made by Socrates which is given priority, this other elements, don’t always agree with this main argument and may undermine it. In the Symposium, the story is in the context of a celebration after a night of heavy drinking in order for some more moderate drinking and philosophical talk and they all give speeches in praise of love; Socrates goes last and his speech is immediately followed by the entrance of a drunken Alcibiades, in the embodiment of Dionysus, who gives a speech in praise of Socrates and forces everyone to drink excessively. Socrates speech incorporates elements from the previous speeches, but disagrees with all, it is spoken in the voice of a priestess named Diotima of suspect authenticity, it includes a myth of the birth of love from Abundance and Poverty, when Abundance is drunk on nectar wine, Aristophanes’ who had tarnished Socrates’ reputation with his play The Clouds, is given a beautiful and amusing story about love being the desire of incomplete individuals to complete themselves in another. I could go on. The closer and closer one looks at these tangled messes of ideas, the more overwhelming it becomes and the more seemingly inconsistent Plato seems to be. One is led into confusion about what Plato is trying to say, if he is trying to say anything or whether he is in fact intentionally undermining his own ideas. It might be in this sense that the middle dialogues are aporetic, that they are self-undermining and confusing. There’s also the late dialogues, of course, which can be even more difficult and confusing, but we won’t talk about those.

In short, this aporetic element of Plato’s dialogues can make his arguments difficult to treat of, since he can be a slippery thinker. Thus, even when I criticize some of his arguments (which I will), we can’t really say whether Plato took those arguments seriously himself.

P.S.: This idea of aporia and aporetic philosophy appeals to me. It can be a good way to bring other’s to wisdom by undermining their ideas, and it also does have a self-satisfying gravitas to it. Thus, there’s a danger of becoming full of yourself. Nonetheless, it’s a good way to go.

Friday, July 18, 2008

Kant's refutation of Idealism

I've decided to open my blog with a discussion of Kant's "Refutation of Idealism", which appears in the revised edition of his First Critique, the Critique of Pure Reason (B274-B279). It's a strong argument but it ultimately is undermined by unwarranted assumptions.

Kant means by idealism, the belief that there is no external world or at least the external world is not indubitable. Kant proves that there is an external world that we can know exists indubitably with our awareness of time. Time is motion and we can only know of motion in comparison to something stationary. Thus, we need to be able to perceive something unmoving to see that something is moving. This is the crux of the argument, since that which is unmoving must be the external world. The nature of consciousness is that it is always in motion, thus it can't be the source of that which is unmoving. Thus we can't have consciousness of motion without consciousness of an external world. Our awareness of time and even of inner consciousness, which is time bound, depends on perception of an external world.

The idea that we need something not in motion to perceive something in motion, I think is right. Einstein uses a thought experiment in his book, Relativity to demonstrate the relativity of motion, which is useful here. Imagine you're an astronaut floating in empty space. If there is no reference point around you, you might perceive yourself as motionless. Let's say another astronaut starts floating towards you: now it looks like he is in motion and you are stationary. But from his perspective you are in motion and he is stationary. In order to perceive motion we need a reference point to compare, since motion is relative.

But I think this thought experiment is in fact doubly useful because it can point us to the unwarranted assumption in Kant's argument. Both astronauts are only in motion relative to something else. There is no absolute motion. In fact, something can appear to be in motion if is in motion relative to something else in motion, just as the earth appears to be spinning around a fixed sun, though the sun is itself flying at great speed through a giant, rotating galaxy. The fact is, we perceive motion in our dreams because we can perceive something in motion relative to something that only appears to be motionless. Kant assumes that we need something that is really in motion to perceive motion and thus to perceive time. But obviously we can perceive motion without anything really in motion. Thus, we can perceive time without an external world.

I admit, of course, that we have no good reason to doubt the external world, but we must admit that Kant has not proven that it is completely indubitable.