Thursday, August 21, 2014

The doctrine of causal closure

Let us take a pair of electrons, Eric and Ed. Eric the electron is an electron in the body of Richard Dawkins. Ed is an electron inside the body of the Archbishop of Canterbury. Knowing this, we might know that Ed is far more likely to be inside of an Anglican Church this Sunday morning than is Eric. But if the physical is causally closed, then where Eric and Ed will be on Sunday morning is either fully determined by the present state of the world at the physical level plus the laws of physics (assuming determinism), or else where Eric and Ed are also affect by quantum-mechanical indeterminism. But this indeterminism, given causal closure, is brute chance and nothing more. It is not a “window” for intentional states to affect the physical. Imagine a being omniscient with respect to the state of the physical world. That physically omniscient being could learn nothing useful about where Eric and Ed will be if it learns that Eric is in the body of an atheist, while Ed is in the body of a Christian. The electrons will go where the laws say they must go, or where chance places them. To say otherwise would be to deny the causal closure of the physical world. 


William said...

So the issue is how the macrophysical world's predictability influences the microphysical? Or the opposite?

Are you saying that the predictability of behavior as intentional violates causal closure?

What if the electrons were on a domestic cat and a seagull, and the question was which one would likely be inside a house? Would that kind of predictability violate causal closure?

Victor Reppert said...

It would have to be predictability from the standpoint of a physically omniscient investigator. For such a a physically omniscient investigator, the presence of the electron inside a cat as opposed to a seagull would make no difference.

For those not so omniscient, it could be helpful.

William said...

I wonder whether such a physically "omniscient" but psychologically neglectful investigator would consider the locations of the people relevant to the location of the electrons. After all, just knowing where I am does not tell me where a single electron in my heart is, at the sub-nanometer scale where such a being would be locating an electron. It would likely scorn our knowledge of a person's likely location as similar to my saying that you are somewhere in the galaxy, that is, as too rough a scale for a truly correct answer.

Limited Perspective said...

I had two semesters of quantum mechanics as part of my Physical Chemistry course work. Much of it was related to the location (actually, orbital) of the electron around the nucleus of the atom. Since I was an average guy, just figuring out the mathematics took enough brain power without asking many philosophical questions about the results. But, if I did ask the professor, “now that we have some insight into the orbital of an electron around the nucleus, how can we find an electron’s location relative to Canterbury Cathedral in Canterbury, Kent,?” I’m sure he would have thought I had gone mad.

This is why I like reading some philosophical websites now that I don’t much care about electron orbitals anymore. Philosophers get to ask the really interesting questions.

If part of science is discovering predictable patterns and then finding the mechanism influencing that pattern, then I think one can ask “why does an individual electron in a particular chemical system have a predictable pattern of location every seven days?” An Anglican Church is a very large location (in terms of volume) compared to the size of an electron and with the Anglican Church being a worldwide and very diverse communion even on Sunday morning, it would be near impossible for science alone to recognize the location pattern. So why do we recognize this pattern?

If however, this predictable seven day event is recognized, how would science go about finding the mechanism causing this? Beats me.

William said...


Yes, interesting from the perspective of the unknowable gaps between microphysical and macrophysical, and between macrophysical and social.

I wonder if physics could come up with a mathematical formula for the probable location of the particle over time. If so, that would constitute an answer at an "atomic" (allowing of course the huge distances, from an atomic perspective, involved) level of description, one that does not exclude other levels of explanation.

I wonder if there is sufficient computing power in the universe to do that level of mathematical description, however, given the size of a dataset accounting for kilometers and months with a particle usually described in units of angstroms and nanoseconds.

WMF said...

I wonder if physics could come up with a mathematical formula for the probable location of the particle over time.

This is already provided by quantum mechanics (in fact, classical mechanics). Except not in the way you ask for it, since "probable location" either assumes positions in a discrete spectrum or the answer is always "in the set of all possible locations".

Unknown said...

" But if the physical is causally closed, then where Eric and Ed will be on Sunday morning is either fully determined by the present state of the world at the physical level plus the laws of physics (assuming determinism), or else where Eric and Ed are also affect by quantum-mechanical indeterminism. But this indeterminism, given causal closure, is brute chance and nothing more." ... Well, no. Indeterminism doesn't necessarily entail non-statistical irregularity. Indeed, Peirce argued in his essay "The Doctrine of Necessity Examined" that statistical regularities arise over time from a universe of chance. You can read his essay here, and you can read more about Peirce's logic here

Victor Reppert said...

When I mentioned brute chance, I was trying to rule out the possibility of someone saying that since the physical is indeterministic, it permits intelligence as a basic cause. The causal closure of the physical excludes that even if determinism is false.

William said...
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William said...

Causal closure of the physical prohibits agency to be able to interfere with measurements done of a closed system. Roughly speaking, it means that certain forms of telekinesis must be false, nothing else.

Calculating all the influences on the net electrical field in which an electron within the body of a living human moves requires the "closed" system to be so large it is _totally incalculable_ if we include the person's body and environs within the system (just closing it within the orbit of the Moon, for example).

So the only way causal closure could ever be shown in practice requires that we exclude people and society from our measurements. If a person messes with our equipment from the outside, say by waving a magnet near the chamber, we discard the artifactual changes.

Causal closure could in principle be falsified (reproducible telekinesis would do it), but it cannot actually (empirically) be proven.

Causal closure is thus a philosophical extension of a simplifying method, and the idea is not entailed by the method at all.

brownmamba said...

This post is an interesting attempt to demonstrate the difficulty of reconciling naturalism with the causal capacities of the mental. Had I decided to go to the Craig/Carroll debate, I would have articulated a similar critique to Dr. Rosenberg: Human bodies are physical; made of atoms and electrons. We can make accurate predictions about where these bodies, and hence electrons, are going based on what humans say (if they're being honest). We don't have to measure the velocity or location of the electrons that make up the body to do this. This seems to show, contrary to Rosenberg, that human sentences do refer to something (in this case a location) and thus there is intentionality in human language.

I doubt, however, that the thought experiment in this post successfully demonstrates that the causal capacities of the mental violates the causal closure of the physical. It seems to presuppose epiphenomenalism. One can respond that beliefs, or intentional states of the mind, are not ontoloigcally distinct from certain complex neurological patterns in the brain. Thus, one could say that a physically omniscient being would already know the beliefs of Dawkins and the religious person.

If one responds to this like Nagel or Leibniz, by saying that no knowledge of the physical would grant knowledge of others' beliefs, then a reply could be that beliefs, like qualia, may be a subjective aspect of reality, but still not ontologically distinct, and thus are still causal.

William said...


"I doubt, however, that the thought experiment in this post successfully demonstrates that the causal capacities of the mental violates the causal closure of the physical."

You understand, I think that there is a difference between disproving or "violating" causal closure and simply seeing it as beside the point?

Causal closure assumes that the system is closed within a potion of spacetime small and isolated enough so that probablistic calculations can be tested.

Any given macroscopic, and most microscopic, biological system or systems we can look at is going to be too large, too complex, and too un-closed for "causal closure" to be tested as regards that system.

Where indeterminism comes up with such a system is that we cannot say, given the microphysical laws, exactly how much of a given change in a physical system is due to deterministic and how much is due to indeterministic influences on the system. We can approximate a few exceptional features, like acceleration in a falling state, for example, but there is much that simply is not categorizable as either "deterministic" or "indeterministic."

So whether causal closure is violated by a living thing is simply not a question that is usually answerable within the bounds of human computation.

This is VERY DIFFERENT from asking whether or not the laws ofphysics are violated. To measure any property for violation,we have to close the system under the property we are measuring,band this tends to restrict what the living thing can do.

Example: conservation of energy. We can put a fish in a closed aquarium and demonstrate the system has conservation of energy. Does that mean that a fish in the aquarium never changes in its energy levels? Absolutely the opposite.

Victor Reppert said...

Brownmamba: In order to test your claim here, I think I need to see if you accept the definition of naturalism that I work from.

William Hasker, in The Emergent Self, (Ithaca, 1999), developed a tripartite definition of minimal materialism which, I believe works also for naturalism. That is, I don’t think any view can be thought to be genuinely naturalistic unless it satisfies these three requirements. It is the view that
1) At the basic level, reality is mechanistic. That is, it lacks intentionality, subjectivity, purposiveness, and normativity. None of these items can enter into a description of reality at the basic level of analysis.
2)The basic level of analysis (which we typically call physics), is causally closed.
3)Whatever else exists must supervene on the basic level. It must be the sort of think that must be the way it is because the physical is the way it is.

On this view it looks like the mental is excluded from "the natural", at least if we are talking about the most basic level of analysis.

brownmamba said...


I've heard of Hasker's work, but unfortunately I am unfamiliar with it. I would like to read it sometime soon.

As for the three requirements, they seem reasonable to me. I interpret "basic level of reality" as the level through which one would have perfect predictive power if one had total knowledge concerning it. It seems that the mental would be left out of the "natural", but only if "the basic level" is all that is considered the natural.

I think the key is the idea of "supervene". It sounds like epiphenomenalism where the mental is like some sort of layer over the components of the brain. If this is the case, then it seems you may be right in you claim that the causal capacity of the mental would violate the causal closure of the physical.

My suggestion, however, was not dissimilar to John Searle's where he compared consciousness to liquidity. Liquidity is not ontologically distinct from the conglomeration of molecules which make up a body of liquid, yet this property is not found on the "basic level". Moreover, liquidity certainly has causal capacities, but is not "supernatural".

I realize you have likely heard of this analogy before and it may fail in certain respects. However, I think it is a useful illustration of what I was trying to say which is that mental states can retain their causal capacities on naturalism, without existing on the most "basic level".

Victor Reppert said...

It seems to me, though, that you could add up particle information and get liquidity as a guaranteed result. There is no normative-non-normative gap to cross, no intentional-non-intentional gap to cross, no no-purpose to purpose gap to cross, and first person to third person gap to cross.

Hal said...

Am going to have to disagree with brownmamba here.

I don't really understand why a naturalist should accept Hasker's definition of materialism. Let alone think that it applicable to naturalism.

As a naturalist, I am committed to the denial that supernatural stuff exists. There is only one kind of stuff: that which is commonly referred to as matter, or physical stuff.

I don't see why that should commit me to the view that the properties of that stuff contain the key to understanding the properties of the kinds of things that are made up of that stuff. Indeed the empirical evidence we have strongly supports the rejection of such a view.

Victor Reppert said...

OK, but what do you mean by supernatural? I feel no need to use the term "supernatural" top describe even God, unless you tell me what natural is supposed to be.

Hal said...

I would think any substance that is not physical would be supernatural given our current state of knowledge of the world. There are many kinds of things that exist in this world, but there is only one substance or kind of stuff that we know to exist: physical stuff.

The words "supernatural" and "natural" can't be given necessary and sufficient definitions. They can vary quite a bit depending on the context in which they are used.

Seems to me that in our present time one key difference between naturalists and super-naturalists is that naturalists place much more emphases on the importance of empirical evidence.

Hal said...

Also, if you prefer not to describe God as a supernatural being, I have no objection.