Wednesday, May 26, 2010

Viability of Theories

Richard Brown is re-reading Plantinga's Against Materialism (PDF) paper and is not impressed. I'm not especially impressed, either, but I found this argument at the end of Richard's post curious:

The very concept of an immaterial substance is unintelligible. Attempts to make them intelligible render them into ordinary physical substances at the next level up, so to speak. And it is of course out of the question to simply say that an immaterial substance is perfectly intelligible since they are just minds (as Plantinga seems to do). It is obvious that there is thinking but it is not at all obvious that an immaterial substance could think. What would that even mean? The upshot then is that substance dualism is not a viable theory.

I think this runs into problems when one considers what actually makes a theory viable rather than glossing it over with this extremely ambiguous question, "What would that even mean?" For it is an extremely ambiguous question. There are several different questions that could be asked in those words, and the answers to each of those questions do not impact on the question of the viability of a theory in the same way. The spread of possibilities when we are asking about the intelligibility of something is closely related.

Imagine someone trying to figure out what scientists mean when they talk about black holes. "What would that even mean?" or "What makes that intelligible?" (asked in good faith) may mean, "What reasons could one have for believing that this is true?" In that case, the physicist would reply by giving his or her reasons to think that there are, in fact, black holes -- certain astronomical phenomena and theoretical considerations based on general relativity, for instance. More broadly, it might mean, "What reasons could one have for believing that this is possible?" The same type of evidence would suffice for answering the question; we are just dealing with a weaker standard of proof.

However, it could be that the concern about intelligibility is not a concern about underlying reasons for thinking that a thing is but concern that we don't know what a thing is. But obviously if you have reasons to believe something exists you know what it is to the extent that you have reasons to believe it; the 'what' that contrasts with 'that' here has to do with our grounds for further inferences. In other words, "What would that even mean?" when applied to black holes would be the question, "On what basis could you say anything more about how this works?" or "What grounds does that provide for further inferences?" The reason that we associate this question with intelligibility is that the greater one's understanding of something, the more easily one can answer further questions. So, for instance, asked this question about black holes, the physicist would respond by talking about the most advanced theories about black holes currently available and the evidence about black holes that underlies them.

It's important to draw the distinction because which side of the distinction one is on at a given moment makes all the difference in the world. One of the most important distinctions to be drawn in any sort of inquiry is the distinction between problems that are problems for a theory and problems that are problems within it. The former put the theory into question; the latter are merely research problems. And making this distinction is essential to determining whether a theory is viable. The physics of black holes is certainly a viable set of theories; they are not made less viable by the fact that there are plenty of things about black holes that are not yet understood or that are purely speculative or that are based on extrapolation from other kinds of cases or that still involve a bit of guesswork. These are all points for further research, not problems for the theory. In talking about evolutionary theory, a biologist may say, "OK, but what does it mean to say that a population of reptile-like theropods eventually became a population of bird-like theropods?" If there were no immediate answer available, the biologist's response would not be, "Oh, then the theory must not be viable because the claim that one became the other is unintelligible." Rather, the biologist would respond by setting out to see what answer the question could be given, which would involve clearing up conceptual confusions, looking at evidence, etc. Such an inquiry might eventually uncover insuperable problems, i.e., problems that put the claim in question rather than simply raise questions for further research, but it might also end up justifying the theory as an excellent theory. A skeptic about evolution might ask, "What would it even mean?" in the same sense as the biologist; in which case he is simply trying to figure out where the theory leads. But he might also be trying to suggest with the question that the whole claim is just unintelligible; in which case the biologist doesn't have to respond by answering the research-problem question but simply by saying why the claim has enough evidential support and theoretical usefulness to merit provisional acceptance and further research. What the skeptic could not do is take the incompleteness of the answer to the research-problem to indicate that it is a fundamental problem for the theory itself; at least, asking "What could that even mean?" in this way would be selective obscurantism, or as we sometimes say more bluntly, playing stupid.

Viability of theories, in other words, is viability in terms of inquiry, and it makes a big difference to inquiry whether we are talking about what leads to a claim or what follows from it. Now, I think it's clear enough that Richard's argument as stated above fails to make this distinction properly. The 'attempts to make intelligible' are dealing with the research-problem question; but whether they fail or not is irrelevant to whether the theory is viable or intelligible, because they are all attempts to extend what we know about immaterial substances on the assumption that they exist. The only question that would be relevant to whether the theory is viable or intelligible would be whether its reasons for saying that thinking could not be a material activity are coherent and reasonable (even if ultimately wrong); but this is not what the argument considers. The argument then seems to founder on considerations of what constitutes viability.

Et Praevalet

Magna Est Veritas
by Coventry Patmore


Here, in this little Bay
Full of tumultuous life and great repose,
Where, twice a day,
The purposeless, glad ocean comes and goes,
Under high cliffs, and far from the huge town,
I sit me down.
For want of me the world's course will not fail;
When all its work is done, the lie shall rot;
The truth is great, and shall prevail,
When none cares whether it prevail or not.

This poem appeared in Patmore's 1877 collection, The Unknown Eros.

Tuesday, May 25, 2010

Bede's Day

Today is the Feast of St. Beda, more widely known as the Venerable Bede. Here is a bit of poetry attributed to him:

Bede's Death Song


Before the needful journey there, no one becomes
wiser of thought than him who necessarily
ponders, before his going-hence,
what good and evil within his soul
after his death-day may be judged.

I say 'attributed' because, while we know Bede recited a poem in Anglo-Saxon on his death-bed, Cuthbert only gives us a Latin paraphrase; starting from the ninth century we find Anglo-Saxon versions of the poem, but they could either be Bede's actual poem or someone's later attempt to recapture it.

The poem, in any case, shows Bede teaching even to his dying day. Bede, of course, is also the patron saint of historians. Bede's classic work, The Ecclesiastical History of England, is easily available online. Bede's historical practices are not completely consistent, but they still show an admirable grasp of the nature of historical evidence and the sort of conclusions that can be drawn from it; he really is an exemplary historian.

Turretin on Infinite Regress

Neither can an infinite series of producing causes be allowed because in causes there must necessarily be some order as to prior and posterior. But an infinite series of producing causes rejects all order, for then no cause would be first; rather all would be middle, having some preceding cause. Indeed there would be no cause which ought not to have infinite superior causes before itself which is impossible [asystaton]). If there were infinite causes before each and every cause, before the whole multitude and collection of causes there would be infinite causes and thus that collection would not be total.

Francis Turretin, Institutes of Elenctic Theology, Third Topic, Question I, Section VI (Giger, tr.).

Monday, May 24, 2010

"Doubtless There Are Other Roads"

The Wayfarer
by Stephen Crane


The wayfarer,
Perceiving the pathway to truth,
Was struck with astonishment.
It was thickly grown with weeds.
“Ha,” he said,
“I see that none has passed here
In a long time.”
Later he saw that each weed
Was a singular knife.
“Well,” he mumbled at last,
“Doubtless there are other roads.”

Sunday, May 23, 2010

Martin Gardner (1914-2010)

Martin Gardner recently died. His writing is very uneven, but he has some gems. His best book-length work is his novel of ideas, The Flight of Peter Fromm (very under-appreciated); but his strength was in smaller works, where an occasionally Chestertonian wit sparks through. He will be missed; he was that rare creature, the genuinely excellent popularizer.

I can't say I was very influenced by him, but, as I said, I liked The Flight of Peter Fromm, and Gardner happens to be where I first read about Raymond Lull.

The Brute Fact Pencil

Nicholas Smith has a really extraordinarily bad argument on the question of whether "God exists" can be a necessary truth:

If that were true than the could be no possible world (=a world that can be described without contradiction) in which God did not exist. But it seems obvious that there can be such a world. Consider this description:

World W = a world in which only a single pencil exists.

It's hard to spot the contradiction in that simple world!

But it's not at all difficult to see that a possible world containing only a pencil is contradictory. When we are talking about possible worlds we are not saying, "Imagine a universe with only a pencil in it at a given point in time." But a possible world in which only a single pencil exists is a possible world in which a pencil exists without anything -- past, present, future, material, immaterial -- to cause it. To say that a world can exist in which only a pencil exists is to say that it is possible for a pencil to exist as a brute fact with no further explanation. But pencils are composed artifacts; as such they are effects, and thus World W is a world in which an effect exists without its cause. That's a contradiction. The only way one can get around this is to argue that pencils can, in fact, be brute facts, i.e., things that are not caused by anything at all, don't necessarily exist, and yet can still happen to exist for no reason whatsoever. But this stretches the concept of a pencil beyond all recognition. Moreover (although full consideration of the question would require a longer argument than this), it is a contradiction for something to exist uncaused and not be necessary, since what exists but is uncaused is something that exists whose existence is not contingent on anything else.

And it's easy to see that the matter is not going to be as easy as Smith suggests, because if God is a necessary part of the explanation for why anything other than God could exist, God is necessary. But it's easy enough to see that this will be a common reason for saying that God is necessary; and therefore no one can be sure of the coherence of the claim that a possible world in which nothing exists but a single nondivine entity unless they are already sure that God is not necessary for the explanation of the existence of any nondivine entity. In other words, the World W argument boils down to the claim, "Well, it just seems obvious that it's possible for God not to exist; just think of what it would be like for God not to exist." But this is just question-begging from the beginning.