Metaphysical Necessity

Yesterday, I asked whether it is a strict logical possibility that William Lane Craig is a lying doofus.  Today, I want to ask whether it is a metaphysical necessity that William Lane Craig is a lying doofus.

Some may be sad to learn that I think that the answer is a resounding "No", but please stay with me as I try to explain how I reach this conclusion.

When reading the Wikipedia page on "metaphysical necessity", we immediately come across words that are faintly familiar:

In philosophy, metaphysical necessity, sometimes called broad logical necessity, is one of many different kinds of necessity, which sits between logical necessity and nomological (or physical) necessity.

Compare this with the words of WLC:

… The answer is “metaphysical possibility.”  This is a modality in between physical possibility and strict logical possibility and is often called “broad logical possibility” by contemporary philosophers.

So, it would appear that WLC took the notion of "broad logical necessity" (likely coined by Plantinga in The Nature of Necessity in 1974), twisted it into a new form, that being "broad logical possibility", and claimed that contemporary philosophers were already talking about it.  I saw the term "metaphysical necessity" in one of the very early documents that refer to "broad logical possibility", the transcript of a talk by … yep, William Lane Craig (The Coherence of Theism).

In this document, you can see evidence of the switch from "broad logical necessity" to the new term "broad logical possibility":

Furthermore, the modality operative in possible worlds semantics is not strict logical necessity/possibility, but broad logical necessity/possibility. Strictly speaking there is no logical impossibility in the proposition The Prime Minister is a prime number; but we should not want to say, therefore, that there is a possible world in which this proposition is true.

It is true that people have been talking about metaphysical necessity for a very long time, but what exactly do we mean by "people" here?  Most of these people have been theists talking about god, or talking about Saul Kripke (who in turn was talking about what was referred to in Strict Logical Possibility as "metaphysical possibility").  Again, when we try to consider things that fall into this category, now considered in terms of necessity, rather than possibility, we can find only one thing that is claimed to be "metaphysically necessary" - and that is a god, most specifically the god of the ontological argument.  There's a neat little Venn diagram on this page that sums things up nicely.

Let us put Kripke's modal logic tautologies aside (ie put aside notions similar to it being "metaphysically necessary" that water is H₂O and vice versa (at which point we need to also put aside the confusion of people who don't accept that ice is also water, despite it having a different name and being a lattice rather than liquid form)).  Other than a god, what does anyone claim to be a "metaphysical necessity"?

When I first started developing the idea for what became Strict Logical Possibility, I was very much thinking about the awkward negation of "strict logical possibility".  People tend to get confused about how modals are negated and casual modern English (particularly as used by Americans) only makes the confusion worse.

For example, if I were to say that "not all" cats are grey, I am not suggesting direct opposite of "all cats are grey" - that is I am not say that all cats are not grey.  If I wanted to say that, I would say "no" cats are grey (or all cats are "not grey".  In clumsy usage, "all cats are not grey" is often meant to say "some cats are grey, but not all of them" - rather than "every single cat that exists is some colour other than grey".  (I'm somewhat ambivalent on the grey/gray divide, although I do see Gray as more of a surname than a colour.)

This confusion carries over to considerations of what is possible/necessary and not possible/necessary (see Plantinga and His BS5).  In brief: that which is not possible cannot be necessary, but that which is not necessary can be possible.  In other words, a lack of necessity is consistent with both possibility and impossibility.  WLC does not fall into the trap of saying explicitly that the non-existence of god is metaphysically impossible, but others certainly do:

William L. Rowe has challenged my claim that there are only two kinds of impossibility, logical and physical, by introducing the concept of metaphysical impossibility — the impossibility which obtains just in case nothing has the power to bring about an individual’s non-existence — and by maintaining that, though God’s non-existence is metaphysically impossible, it does not follow that it is logically impossible as well.

And the ontological argument is based very much on the notion that the non-existence of the god in question is metaphysically impossible - which is to claim that the existence of god is metaphysically necessary.  WLC certainly makes the claim that the existence of his god is a metaphysical necessity:

(blah blah blah, blah blah) … Thus, it is metaphysically necessary that God exists.

But now we are back to the question of what things are metaphysically necessary - if there is nothing else than god in this category (and possibly all those tautological claims that things are the things that they are), then surely the claim that god is "metaphysically necessary" has no teeth whatsoever.  God would have the precisely the sort of "metaphysically necessary" existence that god has (which could easily be no existence whatsoever) and god would have the precisely the same characteristics that god has (being spaceless, timeless, immaterial and non-existent).

WLC goes on in the article linked above to write:

We have here the germ of the ontological argument for God's existence. For if it is possible that God exists, there is a possible world in which God has necessary existence. But then He exists in every world, including this one. Thus, the atheist is thrust into the awkward position of having to say that God's existence is impossible. It is not enough to say that in fact God does not exist; the atheist must hold that it is impossible that God exists—a much more radical claim!

He's claiming here that, because the atheist disagrees with the claim that the existence of god is a (metaphysical) necessity, she needs to hold that existence of god is a (metaphysical) impossibility - perhaps even to the extent that the non-existence of god is a metaphysical necessity.  This is a false dilemma built on a(n implied) begged question - buried in the fact that the only object that is asserted to have a metaphysically necessary existence is a god.  The atheist is quite entitled to allow that gods are a metaphysical possibility, whatever is actually meant by that, while holding that none actually exist (for reasons other than metaphysical necessity/possibility).

Finally, I did say that I did not want to claim that is a metaphysical necessity that WLC is a lying doofus.  I think it's quite reasonable to be averse to putting the assertion "god exists" on a par with "WLC is a lying doofus".  After all, I am quite convinced that god does not exist.

Strict Logical Possibility

Is it a strict logical possibility that William Lane Craig is a lying doofus?

While this might seem like a totally uncalled for attack on WLC's person, it is merely meant as an example of how we might think about "strict logical possibility".

First we need to define our terms.  When we look up "strict logical necessity" we might be disturbed to note that there are only 35 hits (excluding the hits that result from this post - update, as of 6 June 2018, there are now 75).  The majority of them (including this post) make reference to WLC or Plantinga.

This led me to believe that "strict logical possibility" is another taxi-cab, a vaguely impressive sounding piece of nonsense created by William Lane Craig.  A bit more manipulation of Google reveals that the phrase might actually have been a William Dembski original from a 2003 document on the flagellum, a phrase that was then resurrected by WLC in 2007.  Dr Glen Martin used the words in that order in 2004, but the use doesn't appear to be intended as a phrase.  I'm not entirely certain that Demski meant it to be a specific phrase either, since he also used "strict logical certainty", "strict logical deduction" and "strict identity" in the same document - so I think we would not be far off the mark if we were to award authorship of this nonsense to WLC.  I was inclined to be generous.  However, I found that there was an earlier clear use of the term, in 2006, by Sean Michael Campbell (nestled in a reference to "strict and broad logical possibility") - but this was in an overview of WLC's Kalam argument and, in the footnotes, Campbell acknowledges helpful conversations with WLC.

Since WLC was likely the person ultimately responsible for the coining of the phrase, we can look to him to see what it means.  WLC first uses the term in "Causal Premiss (sic) of the Kalam Argument":

Your first question is, “What is the sense of ‘possibility’ here?”  The answer is “metaphysical possibility.”  This is a modality in between physical possibility and strict logical possibility and is often called “broad logical possibility” by contemporary philosophers.  To illustrate, it is strictly logically possible that “The Prime Minister is a prime number” (there is no logical contradiction here); but, notwithstanding, such a thing is metaphysically impossible (incapable of actualization).  There are all sorts of truths—like “Everything that has a shape has a size,” “Nothing can be red all over and green all over,” “No event precedes itself,” etc.—which are not strictly logically necessary but are, I think, metaphysically necessary.  I think that the first premiss of the kalam argument is a metaphysically necessary truth.

I note that "broad logical possibility" was not a term used often by "contemporary philosophers".  It was a term used once, by one guy, after chatting with WLC.  Making such a statement is what contemporary philosophers refer to as "a lie".

Sadly, WLC doesn’t really define "strict logical possibility".  Although he does hint that something has "strict logical possibility" when it doesn't entail a logical contradiction, it isn't clear whether this is key to defining the term or merely a feature of things that have "strict logical possibility".  Fortunately, we have a later reference to the phrase to work from, a quite recent one - In what sense is it impossible for the universe to come from nothing? - 11 September 2016.

When the atheist professor says that “it may be possible that something began to exist out of nothing because that statement did not involve a contradiction,” he is talking about strict logical possibility. He’s quite right that “The universe began to exist out of nothing” involves no logical contradiction and is therefore strictly logically possible. Where he errs is thinking that this is of any philosophical significance.

So, "strict logical possibility" equals "not entailing a contradiction".  This is a construction that is bound to end in tears, since it's hiding a negation in a phrase with two adjectives and a noun - a noun that is conjugated from yet another adjective (ie possible).  And WLC just leaps right in to discuss the impossible, negation of the possible.  He's canny though, since he doesn't talk about "strict logical impossibility" - he merely talks about "broad logical impossibility" (and "metaphysical impossibility", more on that in a moment).

WLC makes clear that "strict and broad logical possibility" (the original phrasing from Campbell) are distinct, meaning that "strict logical possibility" is distinct from "broad logical possibility" and "broad logical possibility" is distinct from "strict logical possibility".  Therefore, we are led to conclude, something that has "broad logical possibility", since it is not "strict logical possibility" can entail a (logical) contradiction.  Read the paragraph above again.  WLC wrote "(X) involves no logical contradiction and is therefore strictly logically possible".

Bizarrely, WLC then writes:

It’s also strictly logically possible that “John is a married bachelor” or that “The Prime Minister is a prime number.” So what? That goes no distance toward showing that married bachelors are metaphysically possible or that it is metaphysically possible that the Prime Minister is a prime number. What we want to know is whether such states of affairs are realizable or actualizable. Could John really be a married bachelor or the Prime Minister a prime (or any other sort of) number?

What the …?

A married bachelor is a classic example of a logical contradiction.  The very term "bachelor" means "unmarried male person".  It is, strictly speaking, logically impossible for John to be a married bachelor.  The only way around this is to get into pointless semantics, to suggest that married does not have to mean what it means, that bachelor could (in an alternate world) mean "person with a big nose" rather than "unmarried male person" - to suggest that, strictly speaking, language is fuzzy and we don't know for sure what any of the terms we are using mean and therefore anything is possible.  This is a very clear indication that WLC is being a doofus.

In the midst of this doofusness, WLC uses the term "metaphysically impossible":

What your theology professor rightly argues is that the universe’s coming into being from nothing is metaphysically impossible. Philosophers typically call this sort of possibility broad logical possibility, in order to distinguish it from strict logical possibility. Speaking in terms of broad logical (or metaphysical) possibility, we claim that coming into being from nothing is broadly logically impossible, just as it is broadly logically impossible that something is colored but unextended or that gold has the atomic number 13.

Note that he's tried to tie "broad logical possibility" to "metaphysical possibility", and claim that "the universe's coming into being from nothing" is "broadly logically impossible" because it's "metaphysically impossible".

Nonsense.  There are two ways of looking at metaphysical possibility.  One is encapsulated in Kripke's classic statement "Water is not H₂O" - this is metaphysically impossible because, by composition, water is H₂O.  This is closely linked to the other way of looking at metaphysical possibility, because there is no possible world in which water would be anything else than H₂O, because that's what water is.  The other view on metaphysical possibility is such that we might discuss other possible circumstances - so it's a metaphysical possibility that this would have been written in German, had the Allies not won World War 2, or in Russian if the USSR had won the Cold War.

For something to be metaphysically impossible (and thus "broadly logically impossible"), it could not have been - even if the world were different.  Examples that we can conjure up for this category are usually the logically contradictory (the time traveller who accidentally kills his mother when she was a toddler), definitional (a sunny day with full cloud cover (our definition usually means at ground level, but above the clouds it is likely to be as sunny as any other day)) or mathematical (1=2).  An example that doesn't quite fit into any of these is the reified privative, like a potful of donut holes (ignoring these sorts of donut holes) and the dark creeping into your house (along with the cold), but I am not sure that this constitutes a metaphysical impossibility, it seems to be more like a simple confusion.

So, when WLC claims that "the universe's coming into being from nothing" cannot be, because it's metaphysically impossible, he is very much begging the question.  He gets away with it because very few make the effort to dig into precisely what metaphysical impossibility is.

Maybe he's not so much of a doofus after all.  Just a big fat liar.  I nevertheless think it's broadly logically possible (and thus metaphysically possible) that he's a lying doofus.