Possible Worlds

I think this lecture helped me make sense of some of the things Nash said in the Intro part of this bit. It's an interesting concept- the whole idea of possible worlds. If you're thinking other dimensions or some sci-fi thing, it's not quite like that. Think philosophy. Like Nash said, it's a tool for understanding the possibility of things. I warn you, it gets a bit heavy at times, but it comes together at the end. 

 A. What is a Possible World? 

It is a way the world could have been, compared to the "real world". 

Think of these circles as possible worlds. Every change in a state of affairs creates a new circle- a new possible world. (Think about a man in the woods, with dozens upon dozens of forks in the road. Sometimes the choices are near endless, and each variation on his route is a possible world. Now multiply that by the number of people that have ever existed in the universe. That'd be the number of Possible worlds. Pretty big huh.)

B. Possible Worlds and Logical Probability 

A state of affairs must be logically possible to exist in a possible world. 

A state of affairs meets these requirements if its definition does not have any logical contradictions.  

C. Logically Possible Vs. Physically Possible

Something can be logically possible, but not physically possible. For instance, is is logically possible to swim across the atlantic ocean, but not physically possible. Not even a little bit. 

Synicuanome- logical consistency. 

Physical possibility can also vary from world to world (Because of the circumstances that can change). For instance- there is a possible world in which I am a cross country runner. Let's say the best in the state. It would be physically possible for me to run a 5:30 mile. If I attempted that in the real world, I would die. 

But, If something is logically impossible, it cannot be physically possible in any world. Take a square circle. It is not logically possible, and therefore is physically impossible (even for God) in any world. 

D. A Possible World is a Complete State of Affairs

Our lives are just a tiny slice of the real world. Imagine that one of these circles (lets say the very first one- top left) is the 'real' thing. It's the one that's actually happening- the one we live in. The other circles are just variations on the real world. 

Plantinga names the real world Charlie (Just to be fun I suppose. I don't quite understand why Nash throws this in here, but it is mildly amusing). 

Nash names his real world "Ronnie". 

Story Time: 

Nash was at a conference where Alvin Plantinga was speaking on the doctrine of Possible Worlds, and the Problem of Evil. Plantinga made the claim, "In every possible world with human beings, they will somehow misuse free will and therefore produce evil."  

Nash's response was something along these lines, "Pardon me Mr. Plantinga, but scripture says that in heaven, there is no sin. Heaven is a possible world, with human beings (and free will), and they never sin." (Nash even admits that he was arrogant enough to believe he had bested Plantinga. He was expecting Plantinga to agree). 

Plantinga response was thus: "Mr. Nash, that just won't do. Heaven is only a slice of a possible world." 

Nash sort of explains the point of this encounter as follows: Heaven is not a possible world- it is a slice of Ronnie. A piece of the real world. It's a big slice- because it's eternal, but it's not a possible world on it's own. (Draw your own conclusions from that, my head's still spinning trying to grasp it's point...) 

E. Books 

For every possible world, there is a "book" about that world. (This is another metaphor...)

All of the propositions for the states of affairs make up the book. 

You cannot add states of affairs into a world, it is complete. (I'm not quite sure what Nash means by this... after contemplating it, I think it might have to do with the variables that change within worlds. Nash doesn't really specify if in a possible world only one thing can be different, or whether multiple variables can be manipulated. I think that he alludes to it here though. He suggests that in a possible world, with it's propositions, a circumstance cannot be "added" in, or changed, because doing so would create another possible world.) 

Because of the number of Possible Worlds- there are that many possible Books. 

There is a Book for the real world as well. Our book is the sum total of propositions as they relate to the states of affairs in our world, past/present/future, as they exist in the mind of God. God knows what's in all of the books. 

Mini Rant: I like that Nash inserted this last bit- "as they exist in the mind of God". Sometimes I feel like when we can't prove something, we automatically assume it's falsehood. This works with some things, but with others, it can be dangerous. As humans, our minds are limited. When it comes to 'extent' statements (Propositions that feel ambiguous- "She likes chocolate a lot") we feel like there are lots of different answers. In everyday terms, we call it opinion. Ultimately though, it's God's 'view' that matters. Ambiguities become clear in the mind of God. Because he is supreme, even if we don't understand something, or cannot fully explain it, that doesn't mean that it cannot exist or be logically possible. 

 F. Contingency and Necessity 

1. Contingent and Necessary Beings

Example of a Contingent being: Humans. We are contingent. We are beings whose non-existence is possible. If your existence is finite, it is contingent. Also, our existence is dependant on variables being manipulated (Food, water, shelter, safety, etc.)

If you are a contingent being, there are possible worlds where you do not, and cannot exist. 

Necessary beings exist in all possible worlds (God is a necessary being). 

2. Contingent and Necessary Truths

Same as Beings. 

 G. Essential and Non-Essential Properties 

Human beings have non-essential properties. Nash uses the example of Baldness (you can guess how much hair he has on his head...). 

An essential property is one that has to be there. We are finite beings. If we weren't, we wouldn't be human. 

On the flip side, God has essential and non-essential properties as well. 

Kenosis Theory says that God gave up some of his attributes to incarnate himself, BUT, if there is a possible world where God gives up an attribute, he ceases to be God. (Notice, there is a difference between attribute and property... Nash doesn't explain that well. When it comes to attributes, he means characteristics. Properties leans more towards decisions. You'll see how in a second...)

So, what is a non-essential property of God? 

Creation. 

How? 

If being the creator was an essential property of God, we'd have pantheism. It would link God and the world in an inseparable way (Instead of God being above and in control). God didn't have to make the world- he chose to. Just like being our savior. He didn't have do, but he did. 

H. Naturalism 

1. Naturalism denies the existence of anything outside the box. (The box refers to Nature or the Universe. See my earlier post on World views). 

2. All you need to disprove Naturalism is 1 thing that exists outside the box. The touchstone proposition of Naturalism is "nothing" outside the box. 

3. Laws of logic must transcend the box. This is ironic, because in order to defend Naturalism- you need the laws of logic. 

Every Naturalist (true naturalist) believes that Naturalism is superior to other worldviews (in essence, they believe it's true). But, to prove that Naturalism is better, he must give evidence, and the evidence must follow the laws of logic. 

Logic cannot be contingent. Why? Because if it was, that would make it finite and dependent on changing variables. In essence, contingent logic is relative truth- which defies the law of non-contradiction. It would be absurd. 

Conclusion (One that Nash has given several times...)-- Naturalism is logically self defeating. 

I. Logic and Laws (Of science, physics, etc.) 

There is a major difference between these things. The laws of say chemistry and physics only exist in some possible worlds. They are contingent. Since the laws of logic transcend the box, they are necessary. They must be infinite and concrete. 

Conclusion

 Lots of stuff covered today. Granted, It was good stuff, but a lot to sift through. Really, this is just a tool for understanding the possibility of things. It's definitely interesting to sit and ponder. Imagine- a near infinite number of Possible Worlds, with different scenarios, choices, people, things, decisions, etc. God knows every one. That blows my mind. 

More stuff on Possible Worlds tomorrow (We get into Middle Knowledge). Stay tuned.  

P.S. Feedback/Comments are seriously welcome! :)