Summula on the IEM

David Papineau:

[T]he case against interactionist dualism hinges crucially on the empirical thesis that all physical effects already have physical causes. It is specifically this claim that makes it difficult to see how dualist states can make a causal difference to the physical world.

But just look at how these physical causes explain the physical effect of, say, actual motion. Why is that car actually moving? Because its wheels are actually moving, because the crankshaft is, because the engine is, because ignited gas is, etc. At each stage, all your explanation amounts to is “A is actually moving if it is connected to an actually moving B, and connected in such a way as to cause actual motion”. It makes no difference if you explain the wheel-motion by the engine-motion or the motion of the gas from the motion of chemical bonds breaking – the actual motion never gets explained, just shown to be a part of a larger, actually moving whole. And so A gets explained by B only by making A a part of the mobile AB, AB gets explained only by making it a part of the mobile ABC… and so either we go on like this to infinity or we say that A is moving because it is moving, and either way we get no explanation. Both options succeed only in making the mobile more complex and no more explained. It is impossible in principle to get anything more than a vacuous tautology – it’s moving because it is.

This is why if you want to explain the actual motion of something you’re forced into positing a non-physical cause. This is an object that, by definition, no one has any sense experience of and so which is understood primarily by negation. Unlike physical causes, this thing cannot change along with what it changes, i.e. unlike a magnetic field or electrical current, which are in flux and changing along with the objects they act on, the explanation of the mobile cannot change along with it.

The immobile explanation of motion (IEM) must be present wherever it can explain. If it is present only at a finite location X, it could never move something out of X. But then it would be impossible to explain the motion out of this location which either means the motion is impossible or that the explanation does not explain. The second is a contradiction; and it is probably impossible to have a space that it was impossible to move out of, though we don’t need to concern ourselves with it since it wouldn’t be a mobile. And so the IEM is completely and present in its totality in every possible division or non-divided portion of finite space.

The IEM shares a property with an abstract entity, i.e. it is wholly present in a diversity of concrete instances, the way redness is perfectly instantiated by any apple in the bushel. Just as a red surface is just as red in the smallest part as in a whole, so the IEM is present in all space, or any domain of nature. But it also shares a property of the concrete in that it is directly responsible for an actual change in the world, unlike abstract entities, which can only cause real events by the mediation of intelligences which are motivated by them. The IEM therefore must be understood as transcending the opposition between the abstract and the concrete. It follows from this that IEM cannot be named by us by any single name, nor can it be understood merely as an abstract entity, like goodness or merely as a concrete entity, like a person desiring the good. We are forced to multiply names without seeing the unity that backgrounds them.

By being entirely present in all space, the IEM is also present in all time; and just as the IEM is present in all spaces without being another spacial object added to them, so too it is present in all times without being another temporal object. Again, just as the IEM exemplifies the abstract and the concrete in all things, it does so in time.

Where intelligence is reduced to the unintelligent, it is seen as explaining away the intelligence. And so if it were ever possible for there to be a motion or action in space that would be described as intelligent or loving, it is necessary for the IEM to be inteligent and loving. But some action is not just possibly but really intelligent, therefore, etc.



  1. January 10, 2015 at 2:59 pm

    On the one hand: I’m not sure that I agree with your take on the matter, for it seems to me that motion A is explained by motion B, motion B is explained by motion C, etc. It does lead to infinite regress, to be sure, but each motion is explained, by the previous. So I’m thinking that there has to be another way to infer a first cause, if a first cause is to be inferable. Perhaps it is the case that the explanatory factors within the regress are not the only explanatory factors.

    On the other hand, I would not call the thesis that all physical effects already have physical causes, if it is meant that they have only physical causes, is an empirical thesis. Rather, wouldn’t it be an empiricist thesis?

    I’ve got some pondering to do.

    • January 10, 2015 at 9:10 pm

      I think Hume makes that argument too (something about an infinite pile of books) but it strikes me as a failure to see the joke of it all. Why bother making an infinite mobile, since the same caliber of explanation can be had by just infinitely dividing the mobile itself? Q: Why is that thing in motion? A: well, because the left half of it is! (applause from the gallery) But why is the left half of it in motion? Because the left-half-of-the-left-half is in motion! It’s the same explanation whether you start small and extend to infinity or start at the maximal and work down infinitely.

  2. January 12, 2015 at 5:49 am

    I must confess I don’t see the similarity. It seems to me that the motion of B might be the cause of the motion of A. And It seems to me that the motion of the left half of A might be the cause of the right half of A. But it does not seem to me that the motion of the left half of the left half of A would be the cause of the motion of the left half of A; it would be a part of it.

    • January 12, 2015 at 1:19 pm

      Look at it like this: if you have some mobile ACBD, did you get it by starting with A and adding the rest, or starting with the whole and cutting it into four parts? So long as you have some homogeneous quantity it makes no difference, and natural motors and moved things have exactly this homogeneous quantity so far as they are considered as actually in motion. Again, if you want to get an infinite mobile you can either start with the smallest thing in your series and add on infinitely or with the largest thing in your series and divide down infinitely.

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