Monday, July 7, 2014

Link: Richard Dawkins and Circular Reasoning

Over at The Cumulative Case, I've made a recent post about Richard Dawkins and his circular reasoning, which echoes a post from a while back here at the Two Books Approach.  In essence, I have attributed a statement to Dr. Dawkins that, if followed to its logical conclusion, means to deny that the fine-tuning of the universe implies the existence of God, is predicated on first assuming God cannot exist.  That is, the probability of God existing is identically zero.  Of course, this isn't logic or reasoning, it is simply blind faith.  Now, I don't suppose I'll know for sure if Dr. Dawkins really holds to this view, so for the benefit of the doubt, I will say that he does not.  Even so, I think it is interesting to unpack what the following statement means: "No matter how improbable this universe is by chance, the probability of God is even less."

An excerpt from the relevant post from The Cumulative Case:
If you start off assuming that God cannot exist, then no amount of evidence, no matter how strong, can budge you.  Dawkins is essentially saying, "I don't care what the scientific evidence for fine tuning says, I will choose to believe that God does not exist." That is not reason or rationality, that is blind belief. Belief, as it were, in spite of the evidence.
For the readers' convenience, I've pasted the relevant point from my old post (note the edit where I have made my statements more circumspect by inserting [many] where the word "all" used to be):
[T]he statement "no matter how improbable this universe is by chance, the probability of God is even less" is tantamount to saying "the probability of God existing is zero." Think about it. The only non-negative number that is guaranteed to be smaller than all positive numbers is zero. This is quite a strong statement. It goes far beyond saying God doesn't exist. It says that God cannot exist. In other words, Dawkins is using an assumption that God cannot exist to try to prove that God does not exist. It is a completely circular argument.
Here's another way to think about it, for the more math-oriented folks. In probability and statistics, the proof we're trying to make is something called a conditional probability. We see an improbable universe around us. What is the probability that God exists given we live in an improbable universe (ie, what's P(G|U))? Using Bayesian inference, we can easily come up with:
P(G|U) = P(G)/(epsilon + P(G)).
Here P(G) is the prior probability that God exists, and "epsilon" is the small chance that this universe came together by coincidence ([many] scientists would agree that epsilon is very small...something like 10^-50 or less). When doing Bayesian inference, you often have to bring in some a priori assumptions to assign prior probabilities (hence the name), so we have to guess at what P(G) is. But you never outright assume that P(G) is identically zero (or one). That would be the same as saying "no matter what our studies tell me, I will choose to believe X." (That's called blind faith.) Usually, when you don't know, you simply set your prior probabilities equal to 1/2. It's easy to see that P(G|U) (the probability that God exists given the universe we live in) would be extremely close to one for any reasonable choice of P(G). The only choice that makes P(G|U) small is P(G) = 0. Which is apparently what Dawkins wants to say.

Wednesday, January 22, 2014

Link: The Inevitable Consequence of An Atheistic Worldview

One of my favorite Christian authors is J. Warner Wallace (Cold Case Christianity), who gave a fantastic lecture here at NC State in December.  I was browsing his blog the other day and came across this piece where he describes an intriguing exchange between some skeptical readers of his blog.

In essence, one of the commenters came out and said in very plain words what the consequences are of an atheistic worldview.  The bottom line is there is no foundation for morality.  I recommend it as a quick read.

Thursday, January 9, 2014

Skeptics don't think Christians think

I have just now come to the realization that, even though there are fantastic arguments in favor of the Christian worldview and of the truth of the bible, many skeptics still think that Christian apologists are charlatans.  That is, these skeptics think that our reasons for belief are grasping at straws, and that our belief comes first, and this faith blinds us to the mistakes we are making in our arguments.  Or worse, that we know our arguments are bad, but we keep advancing them in hopes to keep the faith alive.

This really hit home with me when I considered several bad arguments against Christianity from the starting assumption that all arguments in favor of Christianity were wrong.  (That is, Christians have zero reason for their belief).  Check these out (and these are just a few):

"You just believe because your parents told you to -- therefore, God doesn't exist."  

This is a terrible argument!  But if you start with the assumption that Christianity has no arguments in its favor, then you see why this is compelling.

"You just believe because you were born in Western society.  If you were born anywhere else, you would have adopted the prevalent religion of that location.  Therefore, all religions are false."

This argument is so empty it's hilarious.  First, even if it were true, it doesn't invalidate Christianity.  And second, it's self-refuting: you could apply this argument to atheism (like I do here in "Objection 1").  So why is it so convincing to so many people?  It's because there is the underlying assumption that religions (especially Christianity) have no basis for their belief!  So you can't apply it to atheism, because that has a basis for its belief (so the assumption goes).

Religions are a mind-virus (a meme).  They spread because of societal and cultural pressures.  Therefore, God doesn't exist.

Again, this argument doesn't hold water unless you're already assuming there are no reasons for belief in God.  And again, this argument can be turned against atheism...but the person putting forth the argument doesn't realize that because they don't realize their implicit (and incorrect) assumption: that atheism has evidence for it but religion does not.