Rumor has it, the very beginning is a good place to start. When defending one's faith, then, it seems to me a good place to start is in discussing why one believes in the existence of God. Or at least, a god (or many for the polytheists out there.) There are many reasons I believe God exists, and many more reasons on top of that for my belief in the God of orthodox Christianity. Over time, I hope to share most, if not all, of these reasons. For now, though, we'll start with my favorite reason for believing in the existence of God. As I mentioned yesterday, this is not meant as a proof; this is one of many arguments that I accept as evidence, the sum of which leads me to my faith.
Geez...I disclaim and explain a lot. Must be the outgrowth of having a Mother working at a law firm.
So, back to it. The formulation for this argument is something along these lines. Humans have free will. This means we have the ability to choose between options, and we have the freedom to choose between options free of interference. The reality of free will is nearly axiomatic; the alternatives are not as often held. The alternative is basically determinism. If we do not have free will, we are "programmed" by biology, physics, chemistry and environment/experience to choose a certain way. An example: Person X faces a choice between action A and action B. If X has free will, X may choose A or B; there is nothing preventing X from choosing either option (though there may be factors making one choice more difficult to make than the other.) If X does not have free will, X will always choose A, or will always choose B, when faced with the same choice, in the same environment, with the same life experiences and biological "state."
How does this belief in free will lead to the existence of God? Well, quite simply, there is no purely naturalistic explanation of free will that is satisfactory. At least not one that I've heard. There are two basic explanations for reality. The first is naturalism, which posits that there is nothing that cannot be explained by purely empirical and natural causes. The second explanation would agree to an extent with naturalism, and accept naturalistic causes for many things. However, it would go further and accept the possibility of supernatural causes as well.
If naturalism is true, and nothing can exist outside of the observable universe, then there cannot be a god. Everything must boil down to our physical universe. The problem with this explanation of reality is that is cannot account for free will. One's brain would be the sole decision making center. This doesn't seem such a problem, as most people believe that anyway. But, if our decisions come solely from our brains, then we are at the mercy of the chemical and physical reactions taking place within our brains. Getting back to our example, if person X lives in a purely naturalistic universe, any decisions made would be "programmed" by naturalistic laws: chemical, physical, cause/effect, stimulus/response. There would be nothing to guide the brain through the decision-making process, and impulses traveling through the brain would be forced, by physical laws, to follow set routes. X wouldn't have freedom because the rules governing nerve transmissions would not allow for brain signals to go but one way at any given junction point.
Of course, the "programming" would change as each decision, or bit of sensory data, modifies the structure of the brain. So, it is conceivable that we would have the illusion of being able to choose since later on X could choose a different alternative when faced with the "same" decision. However, since experience and environment (via naturalistic causes) have modified the brain, this second decision is not really from the same choice at all. Part of the environment is different from when the first choice was made, and a vital part of the environment at that. So the choice, while appearing to be different, would still be forced by naturalistic laws, ergo is not really free will.
So I find the naturalistic explanation insufficient to account for free will. Of course, I could be wrong, and I am "programmed" to believe in free will, and to type what I am typing now. In that case, those who disagree shouldn't call me foolish - I'm only doing what I'm programmed to do. Though, I guess, maybe calling me foolish is what they're programmed to do...
This leaves a mix of naturalistic and supernaturalistic explanations for free will. That is, there is a physical component to decision making, which involves naturalistic rules and processes. On top of this, there is a supernatural component that guides, and can "overrule" the naturalistic rules and processes. This I would say is our soul. The human soul could not be naturalistic, else it would act/react to stimuli according to natural laws, and again would mean we have no free will. It'd just be another layer of physical programming.
(You might ask why the physical component would have to exist, and why free will couldn't exist entirely within the soul. It is obvious to me that the impact of such things as drugs and alcohol on a person's decision making process proves that there is an active physical component that can be impacted by naturalistic causes.)
So, the soul is supernatural. This would allow for free will, as it would be unconstrained by physical laws, though as I noted above, the decision making process could be impacted by naturalistic events and input. It also introduces the possibility of other supernatural "things" like God. Since the soul could not spring from naturalistic causes, it would have to come from a supernatural source. This source, then, would be God. I haven't yet addressed what this God would be like, or provided any attributes. All I have argued (and whether coherently or not, I'm not sure) is that granting the existence of free will necessitates the acceptance of the supernatural. In later posts I'll talk about why I believe this God has certain attributes.
In summary (you're probably wondering why I didn't start here and save you the trouble of reading the volume above):
1) Only an explanation of reality that includes the supernatural (i.e. the soul) can account for free will
2) Humans have free will
3) Therefore, humans exist in a reality that includes the supernatural (i.e. a soul)
I think that concludes argument #1. I'm sure I'll come up with clearer formulations later on, but I'll go with it for now. Now I'm off to other things. Namely, trying to figure out why St. Cloud, MN is colder than the South Pole at the moment. That's just not right...
God bless (and have a good weekend!)