Christian Logic -- Is it Different?
In response to a post that I made on Tuesday, an anonymous commenter (*sigh*) made a rather ascerbic comment about Christian thought which I thought deserved more attention than an exchange of comments. As I read it, Anonymous' comment shows a misunderstanding of the probative value of logic. While you can re-read the comment in its entirety by the link, I will summarize it for purposes of this post.
Anonymous used an e-mail from a Prof. Welty that he contends shows that Christian logic can be used to "defend the idea that we have one leg." The e-mail began with two claims:
A: Everybody except me has one leg.
B: My memory is that almost everybody has two legs.
Of course, this is not a logic syllogism. It is simply a couple of statements which appear contradictory. Ignoring for the moment the idea that the person making the claim is somehow singled out as an exception to the rule that everyone has one leg (why this exception is being made is unexplained), the question that arises is "why would a person whose memory is that everybody has two legs make a claim that everyone except me has one leg?" In other words, because of what looks to be a contradiction, either A or B is wrong -- so the argument goes.
But the e-mail fills in another factor that seems to make it possible to read A and B consistently, i.e., makes sense of why everyone (but me) has one leg while my memory says that everyone has two legs. Essentially, it is a call back to Rene Descartes' "evil demon" that is intent on fooling me.
C: My memory has been corrupted by demons.
Is this possible? Yes, it is possible. Is it likely? No. But here's something that you need to be aware of when using formal logic: Any possible facts that can make two inconsistent statements read consistently defeats the idea of a contradiction. In other words, as long as the person making the claim can come up with any possible scenario that makes sense that defeats a potential contradiction, the contradiction is merely an inconsistency that can be harmonized.
By inserting the idea of demons, have I shown that demons, in fact, corrupted my memory? Of course not. All I have done is inserted into the conversation a possible fact that makes the two statements read harmoniously. If true, then there is no inconsistency between my memory of people having two legs and the fact that they only have one leg. The difference in facts have been explained. However, simply making the claim that demons have corrupted my memory does not make the claim true. There are still questions that arise concerning whether there are such demons and whether they have clouded my memory. These are additional facts that need to be determined, and logic alone cannot prove or disprove their existence or activities. That needs to be established by the evidence.
The comment ends by quoting the e-mail which says: "You've applied [Alvin]Plantinga's procedure as a means of proving that [A] and [B] are consistent. But then, with the above example, you are illustrating for us the *cogency* of Plantinga's procedure! You are not undermining it!" In response, Anonymous comments:
I think *cogent* Christian arguments leave a lot to be desired, if they can be used to show that human beings only have one leg.
First, there is no such thing as "Christian" logic. Logic cares not for religion or philosophy. It is a very exacting way of looking at arguments for flaws in rationality. As such, either the argument stands or falls on its own merits. There are no "Christian" or "Non-Christian" arguments in this sense.
Second, the argument does not show that people only have one leg. It shows that there is a possiblity that the idea that we have only one leg and the memory that we have two legs can be read to be logically consistent. However, to show that there is a possible harmonization of the two widely inconsistent views is a far cry from proving that the two are consistent.
In the case of the possiblity that demons are tampering with my memory, I have previously written about Rene Descartes and the reason that I believe that it is logically unwarranted to believe in such demons. As I stated there:
. . . Descartes is wrong because by positing a evil, malignant demon, he is violating Occam's Razor. Now, Occam's Razor, sometimes called "Ockham's Razor" (by Sir William of Occam or Ockham, another Christian with a few interesting variations in this theology), says: "Don't multiply entities beyond necessity." Roughly translated, this means that we shouldn't posit the existence of causes if there is other simpler explanation for the matter being explained. As John Mark Reynolds facetiously put it in a talk I heard him give, it may be that the reason that I am writing such stupid things because there is an invisible pink unicorn behind me putting a horn in my back making stupid statements come out. But there is no reason to posit the existence of such a pink unicorn when there is a much simpler explanation: I am being stupid. (Note, this is a facetious statement--I don't think Dr. Reynolds, or myself for that matter, is stupid in the slightest. But it does illustrate what Occam's Razor is intended to prevent: the unnecessary multiplication of entities.). In the case of Descartes, Occam's Razor would say "why posit the existence of an evil, malevolent demon to explain why the real world appears to exist when there exists a simpler explanation: the real world does exist as we perceive it?" It seems to me that this is correct, and that Descartes was necessarily wrong in positing such a being in order to so dramatically doubting his senses in the first place.
In the case of the e-mail example, there is no reason to posit the existence of demons to explain the inconsistency between A (the supposed fact that everyone but me has one leg) and B (my memory that everyone has two legs). To add demons into the fray simply to make the two statements read consistently -- unless I have stronger reasons to believe that such demons do exist and that they are messing with my memory -- is to violate Occam's Razor since it "multiplies entities" where a much simpler explanation exists, e.g., either my memory is wrong or my supposed fact is wrong.
Thus, I don't believe that the e-mail does what Anonymous seems to assert. It does not prove that Christian argument can show that people only have one leg. Rather it shows (as logic applied by non-Christians must also show) that any possible harmonization makes defeats a claim of contradiction. It can also be used to illustrate (as I have done here) that logic alone cannot be used to reject a possible harmonizing explanation that can make the two contrary statements be read consistently. Nevertheless, in this case there is at least one logical reason to reject the harmonizing claim (memory-altering demons violate Occam's Razor) that makes the two differing facts read consistently. Does that prove that such demons don't exist? No, it does not prove that. What it does mean is that absent further evidence for the existence of the memory-altering demons, I can rationally reject them as a reason for the inconsistency even if I cannot claim that their existence is impossible as a matter of logic.
I believe that I have shown that in this argument, I have a leg to stand on.