Possible Worlds: An Answer to a student

Here is an answer I gave to a student of mine asking about what a possible world is meant to mean in regards to philosophy, enjoy!

Colin,

Whenever you hear someone talking about possible worlds its important to know exactly what they mean, so I am glad you asked about this. I am by no means an expert so I will take some aid from Dr.Craig on this as he evaluates the way Alvin Plantinga sets up his version of the Ontological Argument.

First off when we speak of possible worlds we don't mean planets or universes rather we mean to speak of a maximal description of reality, or basically the way reality might be. Plantinga and others use a huge conjunction of p&q&r&s..., whose individual conjuncts are the propositions p,q,r,s...Thus a possible world is a conjunction which comprises every proposition or its contradictory, so that it yields a maximal description of reality - nothing is left out of such a description. By negating different conjuncts in a maximal description we can arrive at different possible worlds, see below for examples of such possible worlds:

W1: p&q&r&s...

W2: p&-q&r&-s... (this is actually supposed to be a negation symbol but gmail won't let me put in the correct symbol)

W3: -p&-q&r&s...
W4: p&q&-r&s...

...

...

...

Now only one of these descriptions will be composed of conjuncts all of which are true and so this will be seen as the way reality actually is, or the actual world.

It is also important to keep in mind that these possible worlds have to have conjuncts that must be capable of being both true individually and together. For example the proposition that the "Prime Minister is a prime number" is not even possibly true, for numbers which are abstract objects cannot be conceivably identical to a concrete object like the Prime Minister. Therefore there is no possible world in which the Prime Minister would be a prime number. However, if you were to say that "John McCain is the President of the United States" though this is false in the actual world (where all the conjuncts are true) this could be true in some maximal description of reality having this relevant proposition as one of its conjuncts (p&-q&-r&s&John McCain is president&...) Now it is similarly to say that "God exists" is true in some maximal description of reality. Now below you will find Plantinga's ontological argument using God as the greatest conceivable being (maximally great being), it is genius how he comes to his conclusion, the conclusion he uses as his reformed epistemology that states that belief in God is a properly basic belief, it is from this argument that we can come to see why he says this:

Plantinga's Ontological Argument:

1. It is possible that a maximally great being exists.

2. If it is possible that a maximally great being exists, then a maximally great being exists in some possible world.

3. If a maximally great being exists in some possible world, then it exists in every possible world.

4. If a maximally great being exists in every possible world, this it exists in the actual world.

5. If a maximally great being exists in the actual world, then a maximally great being exists.

6 Therefore, a maximally great being exits.

According to Craig most philosophers don't even argue about premises 2-5, they agree if God's existence is even possible, then he must exist. The arguments are over whether there is warrant for believing that a maximally great being exists which is premise 1. People complain that its a logically incoherent statement like a married bachelor. I don't see how a maximally great being is even remotely incoherent. Most detractors of the first premise will say things like the concept of "a most perfect island" or "a necessarily existent lion" also seem prima facie coherent concepts but I hope you see how this is grossly misunderstood. A most perfect island isn't truly that, what if I wanted softer sand, more alcohol in my drinks, a brighter sun, more palm trees. The same goes for the lion, for if it was possible that a lion could exist in every possible world that description of the lion wouldn't be true of a lion at all. By contrast when Plantinga speaks about maximal excellence he is referring to intrinsic maximal values, for example omniscience is the property of knowing any and all truth, its impossible to know anymore truth, but when thinking about an island as I said above you could always add different things to make it better, those things are subjective. Also a material thing cannot transcend all of space-time, density and or temperature, however, a maximally great being, if it is immaterial (metaphysical), could transcend such physical limitations and so be conceived as necessarily existent. 

One then might say how do we know this being transcends physical limitations making it a metaphysically necessary being? Well we covered the necessity for a being outside of the physical world when we touched on the Cosmological arguments and hopefully your on board there (I hope you are comfortable defending the premises of those arguments, that article from Dr. Craig should have helped a little). Here is an argument Dr. Craig offers from a conceptualist point of view for God's existence:

1. Abstract objects, such as numbers and propositions, are either independently existing realities or else concepts in some mind.

2. Abstract objects are not independently existing realities.

3. If abstract objects are concepts in some mind, then an omniscient, metaphysically necessary being exists.

4. Therefore, an omniscient, metaphysically necessary being exists.

As premise 2 states we can defend this by asking ourselves if the number 7 exists independently of a mind, I would have to say it most certainly doesn't. It also goes to note that abstract objects don't exist in causal relations, for example, the number 7 doesn't cause anything at all, this should help when defending the cosmological argument and showing the necessity of a metaphysically necessary being as the agent which acted in causal relation with the creation of the universe. So if number 2 is true then according to 1, 3 has to follow as the explanation therefore the conclusion follows logically from the premises.

Also, keep in mind as we understand the concept of God He is in an immaterial existent mind, or a metaphysical being, which shows where we get the description of the mind in premise 3.

I hope this stuff helps. I love how Dr. Craig speaks about the use of these theistic arguments when he writes, "theistic arguments need not be taken like links in a chain, in which one link follows another so that the chain is only as strong as its weakest link. Rather they are like links in a coat of chain mail, in which all of the links reinforce one another so that the strength of the whole exceeds that of any single link."

Bottom line, when used as a whole argument for the existence of God, the Cosmological argument, Ontological argument, Moral argument, Teleological argument and so on can be employed to make an effective case for theism. Once we break the bonds of disbelief in God then we can present the gospel in its entirety to a lost soul or souls that need to hear the saving grace of our Lord Jesus Christ.

I hope this helped you and didn't confuse you, it was confusing to me in the beginning (what am I saying, it was confusing me while I was typing it!!!) but stick with it and hopefully you can see how it makes sense.

Let me know if I can help in any other way, your questions help me to continue to grow in my understanding of the nature and existence of our Heavenly father.

God Bless little brother!

p.s To answer your question... the possible world does have to be logically coherent...hopefully I answered that in the above response...I guess I could have just said yes to your question and that would have saved you a lot of time reading this, oh well, it was fun typing!

The Power of His Word

So reading through Bill Hybels latest book "The Power of a Whisper" I was inspired to share this quick quote he has about Jesus overcoming temptation from Satan after his 40 day fast in the desert. Here's what it says:

"When the evil one fought dirty, Jesus didn't rely on a community of friends to help him, his amazing prayer life or even his intimate connection with the Father. Rather, in the heat of battle, Jesus relied on the concrete truth of God's Word to counter the temptations leveled his way. Having spent his earthly years saturating himself with Scripture, he was fully equipped with truth to silence Satan's lies.

You and I would do well to follow suit."

In this story we can see the value of knowing the word of God. It can help us from temptation, anger, anxiety or anything else we are facing. Find some helpful verses, memorize them and implement them when the world attacks. You will see your Heavenly Father is faithful to come to the rescue through the power of His word!

The heavens declare...

This morning just thinking about the vastness of space I was reminded what the psalmist wrote when he said, "The heavens declare the glory of God..." -Psalms 19:1 ASV 

But what might this mean exactly? I mean can't the universe explain its own-self just fine? We don't need to look at the galaxies and posit the glory of God, we can see the glory of naturalism!

Sadly, this is how most people are taught in universities and school campuses around the country. The universe is eternal (even though modern cosmology has resounded that the universe had a beginning a finite time ago), even if its not eternal, the universe could have caused itself to come into being. This statement is mind numbingly absurd. It would raise a few questions that must then be answered by the person claiming this position:

1. Can nothing cause something?

2. What was causally prior to the universe?

3. How could something immaterial (the pre-existing universe) become material (the current universe)?

4. Is the universe itself all-powerful and personal?

There are surely more questions for the naturalist raising these points about the universe’s "ultimate bootstrapping trick"[1] as Daniel Dennett pointed out, but they can wait until we hear them respond to these first.

The hard part about positing the universe as the cause for itself is that you would have to answer the question why anything or everything doesn’t just pop into existence out of nothing. Why for example hasn’t an elephant popped into being right now out of nothing to smash my computer? By the way if this happens, I will be converted immediately!

The truth is this sort of thing has never happened in all of history so why should the universe be any different?

Instead I think it highly probable and logical to posit an external first cause of the universe. Well what should the nature of the first cause look like? I will let the professionals answer this one for us, Dr. Craig take it away:

“This transcendent cause must therefore be changeless and immaterial, ... such a cause must be beginningless and uncaused ... this entity must be unimaginably powerful ... Finally, and most remarkably, such a transcendent cause is plausibly to be taken to be personal.”[2]

As Craig points out the nature of this cause must embody a varying amount of traits all of which we know do not exist when speaking in reference to the known universe, therefore positing the universe as the cause for itself continues to remain an absurdity to those who seriously consider the question on the origins of the universe.

As I stated in the beginning here, “the heavens declare the glory of God” and in the description given by Craig one can certainly see the glory of this first cause loud and clear in the very nature of what most perceive God to be.

---

[1] Daniel Dennett, Breaking the Spell (New York: Viking, 2006), 244.

[2] William Lane Craig, Reasonable Faith: Christian Truth and Apologetics (Wheaton, Ill.: Crossway, 2008), 152.

The Moral Argument from our 5 senses

Here is an addition to the Moral Argument in reference to skepticism about our five senses (touch, smell, taste, sight, hearing) and skepticism about our moral sense (Justice, Greed and etc.). This is in objection to the stance of Atheistic Moral Platonism.

Moral Sense:

1.     If a moral sense can exist necessarily without persons, then God does not exist

2.     Moral senses cannot exist necessarily without persons.

3.     Therefore, God exists.

Five Senses:

1.     If our five senses can exist necessarily without persons, then God does not exist.

2.     Our five senses cannot exist necessarily without persons.

3.     Therefore, God exists.

The ultimate question is, are these two arguments and there conclusions more plausible than their denials?

If you think about Justice as a moral sense, can Justice itself be Just? Of course not! Justice is merely a distinction of persons. It requires a person to be Just to deliver Justice. But Justice cannot by itself be just, for if it could then other senses such as love, greed and so forth would be independent entities embodying some sort of physical-metaphysical body which is an absurdity. Therefore moral senses require persons in which to exist.

Think next about our 5 senses. Can touch do anything without a hand or a body? Can taste do anything without a mouth or a liquid or food? It is true that senses cannot exist necessarily out of their own nature because without persons the five senses simply do not exist.

We could say, "well obviously this is true because I didn’t hang out with taste today" or "I didn’t go on a run with greed earlier", but the question remains is the existence of moral sense and the five senses more plausible based on Atheistic Naturalism or on Theism? Can the natural evolution of species account for the moral sense of justice? Did these things merely evolve simultaneously to meet together in the form of Homo sapiens? According to William Lane Craig, he sees William Sorley answer this question thusly, 

“it is far more plausible to regard both the natural realm and the moral realm under the hegemony of a divine Creator and Lawgiver than to think that these two entirely independent orders of reality just happened to mesh.”[1]

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[1] William Lane Craig, Reasonable Faith: Christian Truth and Apologetics (Wheaton, Ill.: Crossway, 2008), 179.

Wash Away

On vacation this past week I couldn't help but recognize the parallel of the ocean water washing away the foot prints in the sand passer's by made. It got me to thinking about sin and how God removes our sins as well, I hope this video touches your heart as it did mine while recording it!

Praise Christ Jesus for the awesome atonement of the cross!