Thursday, 2 March 2017

A Good Reason for WLC's Modus Tollens

I've railed elsewhere about the fact that WLC's morality argument is posed confusingly; in modus tollens form rather than the (more standard) modus ponens form.  To clarify, the argument:
  • If P then Q
  • P
  • Therefore, Q

is more straightforward than:
  • If not Q then not P
  • P
  • Therefore, Q

So, why use the latter rather than the former?

I've also pointed out that WLC himself torpedoes his own argument when appealing to vacuous truth (which he calls "trivial truth", perhaps because it thus seems as if he is referring to a Nils Bohr quotation).

What I have come to realise is not only that WLC possibly was aware of what he was doing when he presented his argument in the form that he did, but also that the problem that he was trying to avoid possibly applies to all arguments for the existence of god.

You see, if WLC had presented the moral argument in the standard modus ponens form, it would look like this:
  • If objective moral values and duties exist then god exists 
  • Objective moral values and duties do exist
  • Therefore, god exists

The issue that WLC was aware of, I think, is that people who are not theists are not as enamoured with "objective moral values and duties" as theists are.  Sure, we agree that if a god of the sort that WLC believes in were to exist, then it would follow that objective moral values and duties would exist, somehow rooted in the existence of that god.  But this is just saying "if a god existed, then the sort of objective moral values and duties that only would exist if a god existed would exist" and non-theists simply do not believe that "the sort of objective moral values and duties that would only exist if a god existed" exist.

So, for us, "objective moral values and duties" of the sort that WLC is referring to constitutes an empty category and therefore it becomes perfectly clear that the major premise of the modus ponens is only vacuously true.  The argument becomes:

  • If the sort of objective moral values and duties that would only exist if a god existed existed then a god would exist
  • The sort of objective moral values and duties that would only exist if a god existed do exist
  • Therefore, a god does exist

We can live with the major premise, since it's vacuously true, but we disagree with the minor premise.

Now, the thing with the vacuously true premise is that it effectively begs the question.  The (actually empty) category that is in question is assumed to not be empty on the basis of an assumption that the conclusion is true.  This is the case, even when you shuffle the terms around and present your argument in modus tollens form.

The trick the WLC then plays, by shuffling his terms around, is to imply that the major premise of his modus tollens is vacuously true:

As you can see, p → q comes out false only when the antecedent clause is true and the consequent clause is false. (I know that seems weird, but that’s the way “→” is understood logically.)

So what does this imply for the first premise of the moral argument?

1. If God does not exist, objective moral values and duties do not exist.

Well, since God does exist, the antecedent clause is false. Therefore, no matter what the consequent clause is, (1) comes out true! (Look at our truth table above.) So it is also true that

1′. If God does not exist, objective moral values and duties do exist.

A falsehood implies anything! So for the theist, (1) and (1′) are said to be trivially true or vacuously true.

Again, can you see?  WLC is pointing out that he is begging the question here (see WLC Being a Duffer for more).  His argument only works for theists who have already committed to the truth of what he is ostensibly trying to prove.  It's a worthless argument.

If an argument is begging the question in its modus ponens form then the argument is begging the question in all correctly stated equivalent forms, including the modus tollens form, such as WLC's stripped down version:

  • If god did not exist then objective moral values and duties would not exist
  • Objective moral values and duties do exist
  • Therefore, god exists


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My other realisation was that this applies to all arguments for god.  If you shuffle the terms around and find that there is begging of the question happening in one (correctly stated) form of the argument, then it's happening in all correctly stated forms of the argument.

This is not a huge realisation on my part, since I thought that was the case in an informal way.  It's just nice to know that it can be shown formally.


Of course, if there is an argument for god which does not include any begging of the question, you are welcome to present your case.

Tuesday, 10 January 2017

A Powerful Argument

In Hands Off Our Logic, God-Boy, I mentioned the fact that Craig refers to his god as “enormously powerful”.  I noted that “power” is time related and want to address a possible wriggle manoeuvre that Craig and his disciples might try.  Possibly, they might argue, Craig is using a different definition of “power”, the “power” that would be necessary to make the universe out of nothing:

If Craig is using a magic version of these concepts, then he’s doing an argument like this:

In The Last Day of the Dinosaurs, the renowned palaeontologist Mathew Wedel holds forth on “how these majestic creatures went extinct”.

(Note that there is no clear indication that Wedel is responsible for the quote that I attributed to him.  Even if he is, it’s a mine-quote, and more than likely it’s a misattributed mine-quote that I took from an inappropriate source, namely tvtropes.org in an article which has a link to a complaint by Wedel that he had been totally misquoted by the production company responsible for the Discovery channel show mentioned.)

“Majesty” derives from the existence of royalty, but where did this “majesty” come from?  It couldn’t have come from human kings and queens because they were not around during the time of the dinosaurs, and dinosaurs had no kings and queens.

(Note that this is a misuse of the term “majestic” and of authority.)

Therefore, when seen as part of a cumulative argument, this shows that there must be a beginningless, uncaused, spaceless, timeless, immaterial, enormously powerful, and sovereign, Personal Creator of the universe!

(Note that this is a very minor change from Craig’s own words as uttered during his debate with Stephen Law.)

In his argument about the creation of the universe however, Craig is specifically talking physics.  In physics, power is the rate at which energy is transferred, used or transformed.  So “enormously powerful” means having the capacity to transfer vast quantities energy (or, alternatively, more modest quantities of energy over very short periods of time).  Hang on a second though … what is energy?  Energy has the SI unit “joule” and 1 joule is 1 kilogram multiplied by the square of 1 metre divided by the square of 1 second.  Both power and energy imply the existence of time and space.

So how did we end up with a spaceless and timeless being who is also “enormously powerful”?

I’ll leave it up to the apologists to provide an answer.  I won’t try to stuff more words in their mouths.


(And, if I am to be completely fair, I have to acknowledge that this simple physics based critique may be unreasonable since I am taking Craig’s gibberish far more seriously than is truly warranted.)