William Lane Craig vs. Stephen Law: Another Case of One Man’s Modus Ponens is Another Man’s Modus Tollens

In October of 2011, William Lane Craig squared off with Stephen Law about the existence of God (video above). Law advanced the hypothesis of an evil god, arguing that just as theodicies aimed at reconciling a good God with evil could be offered, so could “theodicies” aimed at reconciling a evil god with good be offered. This possibility is supposed to discredit theodicies for a good God. Craig accepts that the evil god theodicies are possible, and that is not unreasonable to accept the possibility of an evil god.

During the rebuttals, it seemed that both Law and Craig were talking past each other. Here’s my attempt to clarify. I think it’s yet another case of “one man’s modus ponens is another man’s modus tollens.” (Hereafter MPMT) In this case I’ll start with  modus tollens first. According to Law:

(1) If theodicies for an evil god can be reasonable, then it’s reasonable to accept the possibility of an evil god.

(2) It’s not reasonable to accept the possibility of an evil god.

(3) Therefore, theodicies for an evil god cannot be reasonable.

Then he continues:

(4) If theodicies for an evil God cannot be reasonable, theodicies for a good God cannot be reasonable.

(5) Therefore, theodicies for a good God cannot be reasonable.

(6) Therefore, it is unreasonable to believe in God.

Most of this is pretty self-explanatory, except (4). One would have to argue that the theodices for a good an evil god are similar enough to support this premise.

Craig’s modus ponens:

(1) If theodicies for an evil god can be reasonable, then it’s reasonable to accept the possibility of an evil god.

(2′) Theodicies for an evil god can be reasonable.

(3′) Therefore, it is reasonable to accept the possibility of an evil god.

And, of course, if Craig’s counter goes through, then (4-6) of Law’s argument breaks down.

Law seemed pretty frustrated with this reply, but didn’t really clearly attempt to refute it. He merely insisted that this wasn’t the way to interpret his argument.

That sort of reply isn’t acceptable. Craig offered a counter argument (on my interpretation), one that needs to be answered. And, as in any case of MPMT, it is a contest between (2) and (2′). Law assumed, and insisted on, (2), but provided no real argument for it. Craig didn’t really argue for (2′) either.

Yet, because Law was on the offence here, I think he needs to support (2). Right now it’s merely an assertion, one that carries a lot of weight in his argument. Craig doesn’t have to accept it. Unless Law supports the idea that the possibility of an evil God is unreasonable (good luck with that — even Descartes struggled with that one), there is no real force behind his argument as a whole.

Perhaps Law is thinking that belief in God in general, whether good or bad, is ridiculous. He’d be in the company of most atheists: they believe God is inherently (apart from any evidence) implausible, (note the many comparisons of God with the Flying Spaghetti Monster). But that’s just an atheist thing. You can’t just assume this in a debate about God without begging the question.

 

Zombies: A Case for God

Zombies are logically possible. That is, we can conceive of them. They aren’t like square circles. Philosophical zombies are human bodies that look and act just like we do, but have no experiences, no inner world. They aren’t conscious in this sense. They will tell you they are conscious if asked, by the way.  For their brain circuits are sufficient for this and any other human behavior.

A world that has complex organisms that do what we do yet lack consciousness is possible. If so, then consciousness is an added feature to a material world.  All of our survival can be explained purely in terms the evolution of mechanisms, without mentioning inner experience even once. Consciousness, defined strictly as inner experience, doesn’t have a real explanatory role.

Thus the philosopher David Chalmers thinks that consciousness is a primitive. It may be a basic feature of the universe, or at least as basic as matter and energy. It doesn’t seem explainable in terms of them. (For more about zombies and materialism, see this blog post from Phillip Goff. For more about the troubles of explaining consciousness, see this blog by Bobby Azarian).

“What does this have to do with God?” you might ask. Well, if there is something more than what physics studies (the material universe), that might open the door for immaterial beings like God. Moreover, given that there is no physical explanation for consciousness, and if it also is a primitive, then consciousness could only come from consciousness. And since God is an always existing conscious being, God could be an explanation for consciousness.

This wouldn’t be enough for a case for God: for one could just say that our consciousness derives from some general consciousness woven throughout the universe, and didn’t come from a particular conscious being. There is additional evidence for God, however, this evidence is problematic to skeptics. But one reason it is problematic may be disarmed by the mystery of consciousness.

The problematic evidence: consider the Kalam Cosmological Argument: The universe had a beginning, and things with beginnings have causes. Therefore, something caused the universe. That something must be outside the universe, and that something isn’t material (otherwise it would be part of the universe). Add to this that other features of the universe, such as the fine-tuning of physical constants for life, seem designed. Perhaps the cause of the universe is an immaterial mind.

The problem with the problematic evidence: we know that many features of our minds depend on physical brains. But there was no cosmic brain existing before the universe! Postulating such a being as an explanation for the universe is ridiculous, as Richard Dawkins argues, for a God like this would have be immensely complex and improbable.

How consciousness helps: Consciousness seems inexplicable in terms of brains. This opens up the possibility of a non-physical explanation. And, for all we know, there might be non-physical ways in which to instantiate other parts of the mind. So there could be such things as minds without problematically complex brains. And these ways, even if complex, might not contribute to improbability like physical complexity does (e.g., even complex mathematical statements are no less probable than simple ones). Thus God may not be such a long shot as Dawkins and others suppose.

It is a bit speculative to speak of such things; but regarding the beginning of the universe, and the fine tuning of the physical constants, it’s no more speculative than any of the other hypotheses floating around (especially the multiverse hypothesis). This, plus the fact that perhaps the most important part of mind can’t be explained purely in terms of physics fits better with this hypothesis than with atheistic naturalism. For not only could God create matter, He can create mind as well. Not so for multiverses. All a multiverse could do is create zombies.

One Man’s Modus Ponens is Another Man’s Modus Tollens

Sometimes you hear this expression “one man’s modus ponens is another man’s modus tollens” (hereafter MPMT) from philosophers and others. Here’s my understanding of it.

Modus Ponens and Modus Tollens are argument forms. Arguments are attempts to support a claim with reasons or evidence. The reasons/evidence are the premises, the claim being supported is the conclusion. Conclusions are often indicated by the keyword therefore.

Modus Ponens:
(1) If A, then B
(2) A
(3) Therefore, B

Example:
If today is Monday, then tomorrow is Tuesday.
Today is Monday.
Therefore, tomorrow is Tuesday.

Modus Tollens:
(1) If A, then B
(2) Not B
(3) Therefore, Not A

Example:
If today is Monday, then tomorrow is Tuesday.
Tomorrow is not Tuesday.
Therefore, today is not Monday.

Now for MPMT. It occurs when there are disagreeing parties. The first offers modus ponens. The opponent agrees with the first premise, but disagrees with the conclusion, and therefore, with the second premise.

It’s form:
Modus Ponens
(1) If A, then B
(2) A
(3) Therefore, B

Opposing Modus Tollens
(1) If A, then B
(2′) Not B
(3′) Therefore, Not A

The result is an battle between (2) and (2′). The first thinks that there is more behind A than Not B. The second thinks there is more behind Not B then A.

Here’s more of a real life example:

Conservative Modus Ponens:
(1) If freedom is more valuable than equality, then the government shouldn’t redistribute wealth.
(2) Freedom is more valuable than equality.
(3) Therefore, the government shouldn’t redistribute wealth.

Liberal Modus Tollens:
(1) If freedom is more valuable than equality, then the government shouldn’t redistribute wealth.
(2′) The government should redistribute wealth.
(3′) Therefore, freedom is not more valuable than equality.

These arguments agree on (1). The idea is that freedom and equality conflict at points. (Example, tall men have an unequal share of dating opportunities. To make things equal, we’d have to force women to consider short men equally. To make everyone equal regarding income, we’d have to prevent some people from earning and keeping more.) They disagree on which of these two have the most behind it: That freedom is more valuable than equality, or that the government should redistribute wealth.