Friday, February 26, 2010

Existence/Essence and the Thomistic and Leibnizian Cosmological Arguments

Among the other divine attributes, God is typically defined by classical theists as being a necessary being. As I pointed out in my last entry, there are two types of necessity: metaphysical and logical. Thomas' arguments (TCA) conclude with a metaphysically, but not necessarily logically, necessary being. To put it succinctly, God exists and must exist in the actual world, given the reality of dependent beings and their corresponding need (in the actual world) for some type of ultimate cause. The Leibnizian argument (LCA), on the other hand, concludes that a logically necessary being (one that exists in all possible worlds, not just our own) exists.

Now, my preference for the TCA may be related to my own personal subscription to a very general Aristotelian philosophy, of which Thomism is an offshoot. One advantage of the TCA is that it starts out with a goal that is, in my opinion, less bold. Further, the TCA is more accommodating to inductive arguments, or arguments to the best explanation. The LCA, on the other hand, requires that God be a logically necessary being; so it isn't even possible for God to not exist. Before I am accused of compromising God's sovereignty and logical necessity, I need to point out that I do believe in both. It's just that the TCA may be more likely to persuade those who are skeptical of talk about "necessary beings" to begin with.

The reason I want to introduce these two seemingly different arguments (which is a bit poetic, given that the two are often confused with one another), is that I think they are capable of complimenting each other quite well. If, for example, we take seriously Thomas' claim that God is not only the First Cause, but also that His existence and essence are identical, we should arrive at the conclusion that God is a logically necessary being. As noted before, this is something the LCA (and not the TCA) sets out to do. Let's think a bit more about what Thomas' claim about God's existence/essence really implies.

A being whose existence and essence are identical must, by definition, be a being whose essence is to exist. This is the type of being that cannot not-be. If, then, there were some possible world in which God does not exist, then His essence would not require His existing. Hence, God must exist in all possible worlds, and therefore be logically necessary.

Now, to make this whole situation even more complicated than it already is, I should note that I find it strange how a number of proponents of the LCA criticize Thomas' view that God's existence and essence are identical. Craig expresses some reservation about this in his contribution to The Rationality of Theism (an excellent short anthology, if I might add). What I want to argue is that if God's existence and essence are not identical, then the LCA is left unintelligible.

Since the LCA concludes that a logically necessary being exists, such a being must exist by its very essence. But, if its existence and essence were not identical, then it could possibly not-be. Indeed, could a being that does not exist by the nature of its very essence truly be necessary? Although I support the LCA, I'd like to hear what more knowledgeable proponents think of this. If my analysis is correct, is the LCA not simply an offshot of the TCA?

Further, it seems to me that both arguments result in the existence of a single necessary being. After all, two beings whose existence and essence are identical would actually be identical beings! God is, as Thomas notes, ipsum esse subsistens: "being itself subsisting."

Monday, February 22, 2010

Does Conceivability Entail Possibility?

As philosophers, we are often in the habit of making claims like the following: "it is impossible for a brick to just pop into existence uncaused out of nothing." Yet, possible worlds semantics throws a monkey wrench into this proposition. For, what if there is a possible world in which things, including bricks, are capable of popping into existence uncaused out of nothing? Most of us do not believe this can happen in the actual world, but it appears to beg the question if we map this principle onto other possible worlds.

This brings up the distinction between metaphysical possibility and logical possibility. It is impossible for me to fly by flapping my arms, but in what sense is this really impossible? Specifically, what is implied by this observation is that it is metaphysically impossible for me to fly by flapping my arms - that is, it is impossible in the actual world. However, one may very well postulate some possible world in which I can fly by flapping my arms, and perhaps this is because there are different natural laws governing that world.

However, the ability to postulate something (or the fact that one may conceive of some possible world in which X is the case), I believe, does not always establish that it really is possible, even in the strictly logical sense. This is especially pertinent whenever we are discussing the existence of a logically necessary being, or a being that exists in all possible worlds. One may very well conceive of a possible world with no necessary being, and without any contradiction to be found, it is said that this truly is a possible world. And, if a necessary being does not exist in any one possible world, it follows that it does not exist in any possible world at all, the actual world included. After all, if a necessary being exists in only some, but not all, possible worlds, it is not necessary to begin with, but contingent.*

Let's turn the tables now, though. It is just as easy for me to conceive of a possible world in which a necessary being does exist, and neither does this appear to be contradictory. Given S5, it follows that a necessary being actually exists. Yet, the opponent of this argument will not accept that a necessary being actually exists. This implies that possibility is not determined by mere conceivability, since the same standard can be used to establish mutually exclusive propositions. Think of it this way:

1. If X is conceivable, then X is possible.
2. It is conceivable that a necessary being does not exist in some possible world.
3. Hence, there is a possible world in which no necessary being exists.
4. Therefore, a necessary being does not exist. (This only follows once "necessity" is understood as logical necessity)
5. It is conceivable that a necessary being exists in some possible world.
6. Hence, there is a possible world in which a necessary being exists.
7. Therefore, a necessary being exists.

(4) and (7) contradict one another, which means that something must be wrong with our starting principle in (1).

*This objection can only apply to arguments that attempt to establish, say, God's logical necessity. They are impertinent to God's metaphysical necessity.

Friday, February 12, 2010

Reply to Victor Stenger - Part 1

Victor Stenger received his Ph.D. in Physics from UCLA in 1963. He has also made some criticisms of organized religion, and theistic belief in general. This entry will be the first of a series of posts responding to arguments that Dr. Stenger has defended in support of atheism. Summaries of his arguments can be found here: God: The Failed Hypothesis.

The first proof that Stenger offers contends that the very concept of God is incoherent. By "God" in this context, Stenger does not mean just any Creator or Supreme Being per se, but specifically the God of classical theism that possesses all possible perfections.

1. God is (by definition) a being than which no greater being can be thought.

This concept of God is what we will call "Anselmian theism" (named after St. Anselm, who defended the ontological argument).

2. Greatness includes the greatness of virtue.

Presumably, a maximally great being (God) must be maximally excellent in every possible world, or else God won't be maximally great to begin with. So far, so good.

3. Therefore, God is a being than which no being could be more virtuous.

(3) follows from (1) and (2).

4. But virtue involves overcoming pains and danger.

It is here that Stenger commits an equivocation. Classical theists have traditionally held that God's virtue is analogical, and not univocal, to human virtue. It is virtuous for a human being to overcome his/her fear of dying in order to fight in battle. This would be an instantiation of the virtue of courage. But, is courage required in order to be perfect in virtue? Consider a man who faces no threat of death, as is the case during a time of great tranquility. Is this person culpable for not fighting? If we take Stenger's argument to its logical conclusion, then we ought to say that the man in our analogy should go looking for a fight in order to prove his courage. Yet, this wouldn't be considered courage at all, but rashness.

I propose that Stenger needs to revise his definition of virtue. Otherwise, he is susceptible to the charge of question-begging. My own definition of "virtue" would be something like this: "a characteristic, or attribute, that results in the inclination to produce the best possible states of affairs."

If one is not satisfied with my own definition, let's take one from the Encarta Dictionary: "1. goodness: the quality of being morally good or righteous". [1]

5. Indeed, a being, can only be properly said to be virtuous if it can suffer pain or be destroyed.

Again, why? What is it about the ability to be destroyed, for example, that causes one to desire the best possible states of affairs?

6. A God that can suffer pain or is destructible is not one than which no greater being can be thought.

In other words, it is greater to exist necessarily than contingently. There's no difficulty here.

7. For you can think of a greater being, one that is nonsuffering and indestructible.

(7) seems to be more plausible than its negation.

8. Therefore, God does not exist.

The argument is logically valid, but we have seen that there are difficulties with (4) and (5). In fact, I would maintain that these two premises are patently false, and if nothing else, incapable of verification (as we will see, one of Stenger's own requirements for rational belief in a proposition is its ability to be empirically verified). With the denial of (4) and (5), his argument, though valid, is unsound.

Works Cited


Tuesday, February 9, 2010

The TCA Made Simple - Revisited

Always looking to simplify my favorite arguments, I think we can make the Thomistic Cosmological Argument (TCA) even more accessible to readers than it already is:

1. Limited things exist.

I trust that this premise will be the least controversial. It will be important, however, to point out that I am using "limited" in the sense of "limited with respect to power." You and I have our limits, as do mountains, trees, solar systems, etc.

2. Every limited thing has a cause.

Why does some limited thing - say, a mountain - exist rather than not? We know that entities, like mountains, have various geological processes that cause their existence. Via induction, we may apply this principle to whatever is limited.

3. If there is no First Cause, then nothing will be caused.

Is the regress of causes found in nature limited or unlimited? Given that each of nature's other attributes is limited (e.g., the mountains), it makes the most sense to say that the regress of causes found in nature is likewise limited. This would require that nature has a First Cause, and confirms our usual illustration of a house requiring a foundation. Making nature infinitely old doesn't avoid this conclusion, either, since an eternal house would still need a foundation.

4. Therefore, a First Cause exists.

(4) follows logically from (1)-(3).

5. Every existing thing is either limited or unlimited.

(5) is true via the law of excluded middle.

6. The First Cause cannot be limited.

In support of (6), we know that if the First Cause were limited, then it would have a cause (see premise [2]). However, if the First Cause has a cause, then it wouldn't be first, which is a contradiction. It also doesn't do any good to ask the rhetorical question, "if everything has a cause, then what caused the First Cause?" For, premise (2) doesn't state that everything has a cause, but that every limited thing has a cause.

7. Hence, the First Cause must be unlimited.

(7) follows from (5) and (6).

8. Whatever is unlimited is supreme.

"Supreme" in this context means "unlimited and unique." The uniqueness of the First Cause can be demonstrated as follows. If there were two unlimited things, then there would be distinctions between them. However, things can only be distinct if one lacks something the other possesses. But, a thing can only lack something if it is limited, and the First Cause is unlimited. Therefore, the First Cause is unique.

9. Therefore, a Supreme Being exists.

If "being" is deemed too personal of a term, then the reader is free to substitute "entity" or "thing."

I'm honestly not impressed by objections to this argument. I think the skeptic's best bet is to reason that the Supreme Being is not a personal God, but something like "Nature itself" or some kind of similar Spinozean concept. Even if this alternative route is taken, the TCA still demonstrates the existence of an unlimited and unique First Cause, which I think is a victory for theologians and natural theology.