Monday, March 3, 2014

Craig, Carroll, and Cause

Since I've been reading about causes, one part of the debate that stood out for me was the fact that neither Carroll nor Craig tried to define "cause." In terms of the debate, this was undoubtedly wise: a long digression on the different definitions of "cause" would probably have lost most of the audience. But it was bad philosophy. Carroll tried to explain that, for a physicist, having a consistent mathematical model that comports with the experimental evidence is all we need. Any discussion of causes and effects will proceed from that model. Craig simply kept repeating his argument from incredulity: a universe can't just pop into being without a reason.

But certainly, how we think about causation affect our ideas on whether a self-contained universe needs a cause.

(By the way, this issue is independent of whether the universe in question has a beginning or not. While it might seem intuitively that a universe that begins is more guilty of "just popping" into existence, it has often been argued that a universe that is infinite in time is no less in need of some sort of external cause or explanation.)

On Hume's regularity view, causation is a matter of constant conjunction: to know that A causes B, we need to know that A is always followed by B. So what we need to do is to make lots of observations of deities, and if "Let there be light!" is always followed by a universe popping into existence, then we can conclude that gods cause universes.

On Wesley Salmon's analysis, a causal process is one that can carry some sort of a mark that transmits from the cause to the effect. It would seem, though, that if God is perfect, God is impossible to mark. Thus, we could never tell if a mark can be passed to the universe.

Another modern approach is to take causation to involve the transmission of a conserved quantity, like energy or momentum. But neither the theist not the atheist would claim that a universe that has a beginning in time was initiated by a transfer of pre-existing energy, so in this case there is no possibility of a cause.

On the Aristotelian-Thomian analysis, causation involves a potentiality becoming actuality, and an external cause is necessary to tip something into actuality. A universe is obviously possible (if it were impossible we wouldn't be here), so on this analysis an external cause is needed to make the universe actual.

So it seems possible, in principle at least, that both Craig and Carroll are right: differing definitions of "cause" may yield different conclusions about whether a self-contained universe requires a cause.


  1. I sent a long comment on this some time ago, but it isn't here; did it get lost on the Internet? If so, I'd like to write it again, but if not I rather not....


  2. Seems to have vanished without a trace - sorry! Please re-post, I always appreciate your comments.

  3. Eh, must be my browser. He eats posts sometimes. Alright, here is a remake:

    I think there are really only two basic models for causation. For the Humean, reality is essentially composed of a manifold of existing things, and we choose to label some "cause". Nearly all of contemporary supposedly "non-Humean" discussion of causation is just a disagreement about what precisely to label as "cause". I'm not familiar with the mark or conserved quantity ideas, but they appear to fall into this camp. So is Caroll's insistence on the importance of models, rather than the mere-label of "cause".

    In contrast, the other view - we can call it the "classical" view - is that causal powers exist. They are not just descriptions. A ball actually pushes another ball upon collision; it isn't that we're labeling a complex dynamics in this way, but rather that the ball actually pushes. Of course, some contemporary analyses are "classical" in this sense. So is the Thomist description.

    So I don't think both Craig and Caroll are right. Either causes are merely descriptions, labels we tack to parts of the model, or they are prescriptive, causal powers that dictate to reality what it should be. My money is on Caroll. But either way, the options are incompatible.

    Now I grant that at the plain level both Craig and Caroll may be talking past each other and be both right, as you describe. My claim is rather that there is a deep underlying incompatibility in the structure of the world implied by their respective views on causality.


  4. I'm not sure what you mean, Yair. Physicists generally believe in causal powers too - doesn't one charge actually push on another charge?

    Maybe you're talking about Humean supervenience?

  5. I am talking about the Humean regularity view of the laws of nature.

    Physicists are generally not very interested in philosophy :-) Those that do think of causality almost invariably reach Carrol's conclusion, in my opinion - that what exists is what's in the models, and 'causes' as such aren't.

    We can explore a model with two particles, and tgeir interaction term, and track the dynamics from initial to final states. But this model doean't iclude 'cause'. We add that when we narrate the model, choosing to label one particle's electric potential (say) as the cause of the other's movement. This becomes even clearer in more conpliicared cases, where counter-factual reasoning is often employed to decide what should count as cause, and with ideterminism which exposes the arbittariness of the labeling system.