Sunday, May 20, 2012

Oerter contra the principle of causality

The Scholastic principle of causality states that any potential, if actualized, must be actualized by something already actual.  (It is also sometimes formulated as the thesis that whatever is moved is moved by another or whatever is changed is changed by another.  But the more technical way of stating it is less potentially misleading for readers unacquainted with Scholastic thinking, who are bound to read things into terms like “motion” or “change” that Scholastic writers do not intend.)

In an earlier post I responded to an objection to the principle raised by physicist Robert Oerter, who has, at his blog, been writing up a series of critical posts on my book The Last Superstition.  Oerter has now posted two further installments in his series, which develop and defend his criticism of the principle of causality.  Let’s take a look.

Quantum mechanics and causality

Recall that in an earlier post Oerter claimed that quantum mechanics casts doubt on the principle of causality insofar as it describes “systems that change from one state to another without any apparent physical ‘trigger.’”  Recall also that I pointed out that it is simply a fallacy to infer from the premise that QM describes such-and-such a state without describing its cause to the conclusion that QM shows that such-and-such a state has no cause.

In the first of the two further installments he’s posted since my response, Oerter replies to this sort of objection as follows:

This is a valid point.  Just because quantum mechanics…  is the most amazingly well-tested, most accurate, most far-reaching description of the universe that we have ever produced, we can't just conclude that it's the end of the story.  Maybe quantum mechanics is incomplete - maybe there is some further, more precise, theory that will tell us about the causes of electron transitions and radioactive decay…

This very point was raised in a famous paper by Einstein, Podolsky, and Rosen, who argued in 1935 that quantum mechanics must be incomplete…  An [sic] major advance came in 1964, when John Bell showed that (under a very general set of assumptions) any attempt to “complete” quantum mechanics would end up making predictions that differed from those of QM.  This led to a series of experiments designed to look for such differences.  The upshot: quantum mechanics has come out the winner in every test to date… 

[A]ny additional “causes” added to quantum mechanics will result in violations of quantum mechanical predictions.

Let's suppose that there is some physical property - something not included in the quantum mechanical description - that determines for each atom exactly when the electron will decay.  Call it property A.  Since property A is a physical property, it must have some physical effect.  If it has some physical effect, then it must be possible to separate out systems with one value of property A from systems with some other value.  That is, we can use property A as a filter…

Applying this filter, we separate out a subset from our original set of identically prepared atoms.  This subset, having a physical difference from the original set, will have a measurably different set of physical properties… Thus, this subset will violate the rules of quantum mechanics. 

Now, I put it to you that the 100-year history of successful predictions of quantum mechanics strongly suggests that there are no such additional physical properties…

End quote.  Now, to see what is wrong with this, recall the analogy I drew in my previous post with Kepler’s laws of planetary motion.  I noted that it would be fallacious to argue from the premise that Kepler’s laws describe the orbits of the planets without making reference to any cause of those orbits to the conclusion that Kepler’s laws show that the orbits of the planets have no cause.  And it would remain fallacious whatever you think about Kepler’s laws and whether or not you think the orbits of the planets have a cause.  For the point has nothing to do with the truth or falsity of either the premise or the conclusion.  It has to do instead with the logical relationship between the premise and conclusion.  The premise doesn’t entail the conclusion, and it doesn’t even make the conclusion more probable.  It is evidentially irrelevant to the conclusion.

Hence, suppose someone who insisted that Kepler’s laws do show that the planetary orbits have no cause responded to criticism of this fallacious inference by saying: “That’s a valid point.  Even though Kepler’s laws have had tremendous predictive success, they may not be the end of the story.  Maybe some future theory will posit some heretofore unknown massive bodies additional to the ones we already know about (the sun, planets, asteroids, etc.), which make the planets orbit the sun in just the way they do.  But the problem is that if there were such further bodies, they would influence the ones we do know about in such a way that their behavior would not match Kepler’s predictions.  So the success of Kepler’s laws strongly suggests that there are no such additional bodies.  So Kepler’s laws really do give us reason to doubt that the orbits of the planets have any cause.”

Such a response would, of course, completely miss the point.  For the point has nothing at all to do with the empirical question of whether there exist some heretofore unknown bodies additional to the sun, planets, asteroids, etc. which exert a causal influence on the rest of the solar system.  The point is much simpler (though also much deeper) than that sort of issue.  It is not a point about the existence of causes of this or that particular kind, but a point about causality as such.  And the point is that Kepler’s laws, which merely describe the behavior of the planets, tell you nothing one way or the other about why the planets behave that way.  They are not even addressing that question.  Hence they cannot answer that question.  Nor (we might note for those who eschew metaphysics) can they tell you whether the question is a good question, whether it has any answer in the first place, etc.  To the issue at hand, they are simply irrelevant.

Now the same thing is true of the relationship between QM and the principle of causality.  To point out that it is fallacious to infer from the premise that QM describes such-and-such a state without describing its cause to the conclusion that QM shows that such-and-such a state has no cause, is not to say that for all we know there may be some heretofore undiscovered physical property which exerts an influence on the energy level of the electron (or whatever).  The point is much simpler (though also much deeper) than that sort of issue.  It is that QM, which merely describes the behavior of a system, tells you nothing one way or the other about why the system behaves that way.  It also tells you nothing one way or the other about whether the question of why it behaves that way is a good question, whether it has any answer in the first place, etc.  To the issue at hand, QM is simply irrelevant.

This naturally brings us to another objection to his position that Oerter considers in his recent post, to the effect that the principle of causality is “a metaphysical premise that can't be contradicted by any possible set of observations.”  Oerter’s reply is that to insist, on metaphysical grounds, that the actualization of a potential must always have a cause is either to beg the question against him, or to rest one’s position on definitions of the key terms (“actuality,” “potentiality,” “change,” etc.) without giving any reason to think that the terms so defined really capture anything in the real world.

To see what is wrong with this response, consider once again the fallacious inference from the premise that Kepler’s laws describe the orbits of the planets without making reference to any cause of those orbits to the conclusion that Kepler’s laws show that the orbits of the planets have no cause.  Suppose that when you pointed out the fallaciousness of this inference to someone who made it, he replied: “Your position either begs the question against me or rests on arbitrary definitions!”  Obviously this too would simply miss the point, since the criticism of the inference in question was not: “The orbits of the planets do have a cause, here’s my theory about what that cause is, here are the technical terms my theory makes use of, etc.”  The criticism was rather: “Whether or not the orbits of the planets really do have a cause, the inference you are making is fallacious, because Kepler’s laws by themselves aren’t even relevant to that particular question.”  Similarly, the inference from the premise that QM describes such-and-such a state without describing its cause to the conclusion that QM shows that such-and-such a state has no cause is fallacious, and it remains fallacious whether or not the principle of causality is true, whether or not the definitions of its key terms have any application to reality, etc.  Even if the Aristotelian position turned out to be false, quantum mechanics wouldn’t be what falsifies it.

Oerter also addresses another potential objection to his position, to the effect that “the laws of quantum mechanics are the cause of the change [i.e. the change described in examples of the sort Oerter appeals to].”  The first part of Oerter’s response is as follows:

This objection can be dismissed easily.  The question is what causes the change to happen at the particular time it happens.  QM is silent on this question.

Further, in most philosophical views of physical laws, the laws have no causal efficacy.  For instance, we might think of laws as just descriptions of the way things actually behave.  But a description of how something happens is not a cause of it happening.  So, the moon's orbit around the earth isn't caused by the law of gravity.  It's caused by the actual gravity of the actual earth. 

Now as it happens I more or less agree with what Oerter says here.  Indeed, it is ironic that he should say it, because it actually supports my position rather than his.  Oerter writes that “we might think of laws as just descriptions of the way things actually behave.”  Exactly.  Laws -- including the laws enshrined in QM -- are descriptive.  They tell you what happens, but they do not tell you why it happens that way.  They may, of course, make reference to particular sorts of causal factors -- gravitation, mass, charge, etc. -- but the explication of these factors itself simply amounts to a further description of what these causes do, not why they do it.  Indeed, the causality as such of gravitation, mass, etc. is, strictly speaking, irrelevant to the laws.  That A and B will behave in such-and-such a way is all the law qua law commits you to; that A is the cause of B drops out as irrelevant.  That is why Newton’s law of universal gravitation was so useful even when we had no clear idea of what gravity was or how it worked.  And that is why positivists could hold that causality was a pre-scientific holdover which could be dispensed with.  They were wrong to hold this, but the point is that they could hold it with a straight face in the first place only because the status of causality as such -- its nature and even its existence -- is something about which the laws of physics themselves (including the laws of QM) are silent.  

But the status of causality as such is precisely what the principle of causality is about.  And that is why QM has nothing to tell us about the principle of causality.  They are simply not addressing the same question.  Given that you have already determined on independent grounds whether or not the principle of causality is true, QM may raise questions about how it is to be understood in contexts like that of the hydrogen atom (to allude to Oerter’s example).  But there is nothing special about QM in that regard.  One billiard ball knocking into another, melting and freezing, electromagnetism, gravitational attraction, plant and animal growth, volitional behavior, divine creation, all involve very different sorts of efficient causality.  There are also distinctions to be drawn between essentially ordered and accidentally ordered causes, between causes that contain what is in their effects formally and those that contain what is in their effects only virtually, between total causes and partial causes, between the causality of substances and that of accidents, and so forth.  If you think that all efficient causality reduces to some crude, deterministic billiard-ball model, then QM might seem to be a challenge to the very notion of causality.  (“Look, there’s no little billiard ball deterministically pushing the electron into a higher energy level!  Causality itself crumbles!”)  But no Aristotelian or Scholastic would buy this simplistic conception of efficient causality in the first place.  (Naturalist critics of Aristotelian-Scholastic arguments rarely beg one question at a time.  They beg whole books full of questions.)

The principle of causality itself does not make any claim about how exactly efficient causes operate in all of these diverse cases.  It just tells us that whatever the details turn out to be, any potential will only be actualized by something already actual.  How does this work out in the case of QM?  This brings us to the second part of Oerter’s response to the claim that the laws of QM are the cause of change.  He writes:

Finally, even if we think of physical laws as having some sort of actual existence and causal efficacy, well, the laws of QM exist right at the moment the electron is excited, so by this view the electron should immediately decay.  In Aristotelian terms, we are looking for the efficient cause: the thing that brings about the change at the instant it occurs.  The laws of physics apply equally to all times; they can't be the reason something happens at some particular time.

(It seems to me that the laws of physics could be considered the formal cause in Aristotelian language.  But Feser says that modern philosophers have abandoned formal (as well as final) causes.  Does anyone know if laws can, or cannot, be considered formal causes?)

The answer to this latter question is: No, laws are not formal causes.  Nor do laws have any sort of independent existence or efficacy as efficient causes.  The correct thing to say from an Aristotelian point of view is rather something like this: Natural substances have essences or substantial forms that ground their characteristic patterns of operation.  For instance, it is in virtue of the substantial form of a tree that it tends to sink roots and grow branches; it is in virtue of the substantial form of water that it tends to freeze at one temperature and boil at another temperature; it is in virtue of something common to the substantial forms of material objects in general that they exert a gravitational pull on each other; and so forth.  Now a “law of nature” is a description of these patterns, a description of how things will tend to operate given their natures, essences, or substantial forms.  The existence and operation of laws of nature thus presupposes the existence and operation of concrete natural substances.  Indeed, strictly speaking it is not the laws that exist and operate; “laws” are mere abstractions from the concrete substances.  What exist and operate are the concrete substances themselves.  The laws are not even formal causes but rather mere descriptions of how things operate given their formal causes, i.e. their substantial forms.  (See chapter 6 of David Oderberg’s Real Essentialism for an important recent treatment of laws of nature from an Aristotelian-Thomistic point of view.) 

[This is, by the way, why “laws of nature” don’t really explain anything, at least not ultimately.  The very idea is a holdover from a time when Descartes, Newton, and Co. wanted to chuck out the Aristotelian framework, and replaced the idea that things operate according to intrinsic natures or substantial forms with the idea of operation according to externally imposed divine commands or “laws.”  Stripped of this theological context, the notion of a “law” must either be cashed out in Aristotelian terms of the kind suggested above, or in other metaphysical terms equally unwelcome to the naturalist, or -- as Nancy Cartwright has pointed out -- collapse into incoherence.  It is ironic that atheists so unreflectively help themselves to an inherently theological idea, albeit an idea derived from modernist rather than Scholastic theology.]

In the case of the hydrogen atom (once again to appeal to Oerter’s example), what we have is a concrete system that behaves in the way described by QM.  Now as I have noted before, whether to give QM a realist (as opposed to an instrumentalist) interpretation in the first place is itself a vexed metaphysical question.  And since it is a metaphysical question, it is precisely the sort of question to which we can legitimately bring to bear considerations like the principle of causality.  So even if there were some conflict between that principle and QM (which, as I have argued, there is not) it wouldn’t follow that we’d have to give up either.  If (as I would claim) we have independent reason to affirm the principle of causality, what would follow from such a conflict is that we should take an instrumentalist rather than realist view of QM -- a position some philosophers and scientists with no Aristotelian ax to grind would adopt in any case.

An interpretation of QM that is both Aristotelian and realist will, naturally, insist that it is not the laws of QM themselves that cause anything, since they are mere abstractions from concrete systems operating in accordance with their substantial forms.  Hence it is in virtue of the substantial form of a hydrogen atom that it will behave in the manner described by QM, just as it is by virtue of the substantial forms of material things in general that they will exert a gravitational attraction on one another.  Now for the Aristotelian, the substantial form of an inanimate substance is not the efficient cause of its natural operations; rather, those operations flow “spontaneously” from it, precisely because it is in the nature of the substance to operate in those ways.  (See James Weisheipl’s Nature and Motion in the Middle Ages for an important treatment of the subject.)  Hence that a planet exerts a gravitational pull is just something it does by virtue of its nature or substantial form; it does not need a continuously operating efficient cause to make it exert such a pull.  That does not mean that there is in no sense an efficient cause of a thing’s natural operations, but that efficient cause is just that which gave the substance in question its substantial form in the first place, i.e. that which generated the substance or brought it into being.  It is not something that needs continuously to operate after the thing is brought into being.  Hence the efficient cause of a planet’s exerting a gravitational pull on other objects is just whatever natural processes brought that planet into existence millions of years ago, thereby giving it the nature or substantial form it has.  Its exerting that pull is now something it just does “spontaneously,” by virtue of its nature.  (Mind you, that does not mean that it can exist or operate even for a moment without a divine sustaining cause; it cannot do so, for reasons I spell out in my ACPQ article “Existential Inertia and the Five Ways.”  But that is a separate issue.  What I am talking about here is whether there needs to be some efficient cause alongside it within the natural order that causes it to exert a gravitational pull.)

Now, along the same lines, we might say that the hydrogen atom also behaves as it does “spontaneously,” simply by virtue of having the substantial form it does.  Why do the electron transitions occur in just the pattern they do?  Because that’s the sort of thing that happens in anything having the substantial form of a hydrogen atom, just as gravitational attraction is the sort of thing that naturally happens in anything having a substantial form of the sort typical of material objects.  What is the efficient cause of this pattern?  The efficient cause is whatever brought a particular hydrogen atom into existence, just as the efficient cause of gravitational attraction is whatever brought a particular material object into existence.  That is one way, anyway, of giving an Aristotelian interpretation of QM phenomena of the sort cited by Oerter, and it is intended only as a sketch made for purposes of illustration rather than a completely worked out account.  But it shows how QM can be naturally fitted into the Aristotelian framework using concepts that already exist within the latter.

Of course, critics of Aristotelianism will reject this way of interpreting what is going on.  Fine and dandy.  (Though please don’t waste everyone’s time with sophomoric Molière-style “dormitive virtue” objections to substantial forms.  I have explained why this objection is no good in The Last Superstition and Aquinas.)  The point is that QM itself gives one no reason whatsoever to reject it.  If the critics of the Aristotelian position are to find rational grounds for rejecting it, they must look elsewhere.

Newton and local motion

In the second of the two installments he’s posted since my initial response to him, Oerter raises the hoary objection from Newton’s law of inertia against the principle that whatever is moved is moved by another.  Now, as I have already noted, the less misleading way of stating the principle is as the thesis that any potential, if actualized, must be actualized by something already actual.  And when it is put that way, it is less obvious that there is any conflict with Newton’s law.  After all, Newton’s law tells us that every body continues in its state of rest or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it.  And how, exactly, does this contradict the thesis that any potential, if actualized, must be actualized by something already actual?
 
The answer is that there is no conflict at all, because (once again) the principle of causality and the laws of physics are not even addressing the same question.  Now I discussed this issue briefly in The Last Superstition, and it is to what I said there that Oerter is responding.  But I addressed the issue at greater length in Aquinas (at pp. 76-79), which it seems Oerter has not read.  And I address it at much greater length still in my paper “The medieval principle of motion and the modern principle of inertia,” which is forthcoming in the Proceedings of the Society for Medieval Logic and Metaphysics (and which, when it appears, should be available online as well as in print).  

I’m not going to repeat everything I’ve said in Aquinas or preempt what I say in the forthcoming paper, but some general remarks should suffice for present purposes.  There are five general reasons why the purported conflict between Newton’s law and the principle of causality is illusory (reasons I develop at length in the paper).  First, there would be no formal contradiction between the two even if they were using “motion” in the same sense.  For like Kepler’s laws and the laws of QM, Newton’s law is descriptive.  It tells us how a body behaves, but not why it behaves that way.  Thus the law does not rule out the thesis that the reason a body so behaves is because of a “mover” which actualizes its potencies for motion.  (To be sure, the law does rule out any scenario where a body continues at rest or uniform rectilinear motion while acted upon by physical forces impressed upon it.  But -- to appeal once again to the analogy with Kepler’s laws -- the principle of causality no more requires that what actualizes a potency is, specifically, a physical force of this sort than to affirm a cause of the orbits of the planets requires positing a special kind of massive body additional to the sun, planets, asteroids, etc.)

Second, Newton’s law and the principle of causality are not in fact using “motion” in precisely the same sense in the first place.  Newton’s law pertains to local motion specifically, i.e. change with respect to place.  The principle of causality applies to change of any kind, which includes not only local motion but change with respect to quantity, change with respect to quality, and change from one substance to another.  Now some might object that these other sorts of change can all be reduced to local motion.  I think that is quite false, but that is neither here nor there for present purposes.  For the deeper point is that when the principle of causality speaks of motion (local or otherwise) what it is talking about is the actualization of potentials.  And Newton’s law simply has nothing whatsoever to say about that.  In particular, when Newton’s law says that a body in motion will tend to stay in motion, it is not asserting that a potential which is being actualized will continue being actualized.  Even if it were suggested that Newton’s law entails this, the point is that that isn’t what the principle of inertia itself, as understood within physics, is saying.  Indeed, the whole aim of early modern physics of the sort practiced by Newton was to provide a description of nature that sidestepped the whole Aristotelian-Scholastic apparatus of actuality and potentiality, substantial forms, and the like.  Modern physics didn’t offer different answers to the questions the Scholastics were asking.  It simply changed the subject.

A third point is that Newtonian inertial motion is often characterized as a “state” -- that is, as the absence of any real change.  Now if such motion really is a state, then there is no conflict with the principle of causality, for if inertial motion involves no real change, than it involves no actualization of potential -- in which case, obviously, it involves no actualization of a potential without a cause.  Indeed, since Newton’s law says that a genuine change in an object’s local motion can occur only if a force acts upon it, the law implicitly affirms the principle of causality!  Hence if inertial motion really is a “state,” then what Newton and his Aristotelian predecessors disagreed about was not whether genuine change requires a cause, but only about whether local motion of a uniform rectilinear sort counts as genuine change.  

A fourth point is that those who assert a conflict between Newton and Aristotle often direct their attacks at a straw man.  In particular, it is sometimes thought that Aristotle and Aquinas maintained that no object can persist in any local motion unless some mover is continuously conjoined to it as an efficient cause.  But in fact they denied this; their view was that an object will tend to move toward its “natural place” simply by virtue of its substantial form, and will do so even in the absence of that which imparted this form, and thus in the absence of that which is the efficient cause of their local motion.  (This is related to the point made earlier about the operations that a substance will carry out “spontaneously” given its substantial form.  And here too, Weisheipl’s book is the place to look for a detailed treatment of the subject.)  To be sure, the idea of “natural place” is a piece of Aristotelian physics (as opposed to metaphysics) that is obsolete; and the violent (as opposed to natural) motions of objects were thought to require some conjoined mover.  But all of that is beside the point.  For the point is that Aristotle’s and Aquinas’s principle of causality in fact did not presuppose that local motion as such requires a continuously conjoined physical cause.

Finally, and as all of this indicates, there can be no conflict between Newton’s law and the principle of causality because the former is a thesis of natural science and the latter a thesis of metaphysics -- or more precisely, of that branch of metaphysics known as the philosophy of nature.  As Bertrand Russell and others with no Aristotelian or theological ax to grind have emphasized, what physics gives us is really only the abstract mathematical structure of the material world.  It does not tell us what fills out that structure, does not tell us the intrinsic nature of the material world.  But that is what metaphysics, and in particular the philosophy of nature, are concerned with.  Moreover, the philosophy of nature, as modern Scholastics have understood it, tells us what the natural world must be like whatever the specific laws of physics, chemistry, etc. turn out to be.  And the Scholastic position is that the distinction between actuality and potentiality, the principle of causality, and other fundamental elements of the Aristotelian conception of nature are among the preconditions of any possible material world susceptible of scientific study.

That is why no findings of empirical science can undermine the claims of metaphysics and the philosophy of nature.  It is also why no findings of empirical science can undermine the Aristotelian-Thomistic arguments for the existence of God, for these are grounded in premises drawn, not from natural science, but from metaphysics and the philosophy of nature.  Now that does not mean that these arguments of natural theology are not susceptible of rational evaluation and criticism.  What it means is that such evaluation and criticism will have to be philosophical and metaphysical, rather than empirical, in nature.  Nor is natural theology in this regard at all different from atheism.  Atheists who think they are arguing from “purely scientific” premises never really are.  They are, without exception, arguing from metaphysical assumptions -- and usually unexamined ones at that -- that are first read into empirical science and then read back out, like the rabbit the magician can pull out of the hat only because he’s first hidden it there.

Readers who disagree with these claims are cordially invited to refute them -- without either begging the question or smuggling in metaphysical assumptions of precisely the sort they deny making.  Good luck with that.

228 comments:

  1. goddinpotty -

    For all numbers a and b, a^2 - b^2 = (a+b)(a-b); therefore, substantial forms exist.

    Reply!

    ReplyDelete
  2. GIP,

    I love dialectic. What I do not love is when someone makes fallacy-ridden arguments, never listens to advice or instruction, never admits defeat and is only interested in winning. This is you. If you were actually debating in good faith and admitting when your (weak) arguments lost to stronger ones, you would be able to improve--and everyone would respect you more. Instead, you present us with "Tlaloc" and automatically assume that Feser and everyone else here is wrong. Present a serious challenge without committing a fallacy, and people will pay attention.

    ReplyDelete
  3. @Michael Brazier
    All integers are bootstrapped out of emptiness by the operation of the mind. They have no 'substantial' existence outside the mind and its operations: http://www.mathpath.org/concepts/number.htm

    ReplyDelete
  4. @Michael Brazier -- define "exist". IOW, I have a fairly good sense in which, say, a chair either exists or does not exist. I also feel like I have a good intuitive sense of what a number is, but I don't know what it means to say "3" exists or does not exist. And I truly have no idea what it means for a substantial form to exist or not exist.

    Actually, don't bother, because I have a new policy of checking out of these comment threads once they get past 200 comments. See you in the next one, perhaps.

    @rank sophist -- the Tlaloc example was an analogy to illustrate a particular pattern of inference, and as such can only be apt or not; it is not a deduction or argument so it can't be fallacious. The entire point of that seems to have escaped you and I'm not in a mood to try to explain it.

    ReplyDelete
  5. the Tlaloc example was an analogy to illustrate a particular pattern of inference, and as such can only be apt or not; it is not a deduction or argument so it can't be fallacious. The entire point of that seems to have escaped you and I'm not in a mood to try to explain it.

    Your unsubstantiated claim that it actually illustrated that certain pattern of inference was what begged the question, since your intention was to use our answers to prove a point. But I can see that you have no plans to change your position as someone who "makes fallacy-ridden arguments, never listens to advice or instruction, never admits defeat and is only interested in winning"; so I have no interest in talking to you further.

    ReplyDelete
  6. Potty... HAS LEFT THE BUILDING!!!

    ReplyDelete
  7. Yup, he picked an arbitrary amount of posts to act as a threshold for decamping from the thread in order to turn tail and run. I wish that I could call the man a sophist -- but that would be too flattering: he lacks the intelligence to think coherently.

    ReplyDelete
  8. The pseudonymous blogger Bonald, an astrophysicist, showed a while back that QM doesn't in fact contradict our common understanding of causality: http://bonald.wordpress.com/in-defense-of-religion/finite-and-unlimited-being/7/#religion9.

    "If things like that could happen, the universe would be completely unintelligible. It would not evolve according to regular laws, as it seems to. How do we explain this? First, let me note two explanations that won’t do. First, we can’t explain why things don’t pop into existence by invoking a law of physics: conservation of mass or energy, symmetries in a Lagrangian, a divergence-free stress-energy tensor, etc. These are just mathematical restatements of the fact that things don’t just pop into existence. Second, we can’t get away with saying that things can pop into existence, but that they probability for its occurrence is low (like quantum tunneling across a high energy barrier), so that it happens sufficiently rarely that it is unnoticed. Suppose this were true, and a certain non-existent object had a certain low probability of popping into existence. I could always imagine another object, no more nonexistent than the first, with all of the same properties but a very high probability of popping. All nonexistent beings are equally nonexistent, so this second kind of object is as valid as the first. If we say that the probability of popping is set by some other object that actually does exist, than that object would be the cause of the other thing’s coming into being. We would have a case of one being acting to cause another, something that doesn’t raise any problems for the intelligibility of the universe. It seems that this type of coming into existence, that of being caused by something that existed already, is the only way that finite beings can come to exist.

    "One might object that things popping into existence uncaused must be possible, because physicists sometimes assert that such things happen: virtual particle-antiparticle pairs pop into and out of existence out of nothing, and the universe itself is said to have popped into existence during the big bang. No doubt physicists do make such claims in popular expositions of their work, but it’s a very sloppy description of the actual theories. I once attended a colloquium at which a string theorist boasted that it had been proven that the universe came into existence out of nothing, but that “nothing” has a structure which they’re still working out. Now, of course, if something has a structure, one with causal effects on the actual universe, it’s most certainly not “nothing”. Similarly, the picture of particles popping into existence uncaused is not a tenable interpretation of quantum field theory. First of all, it’s not just anything, but standard-model particles in particular combinations that are said to populate the vacuum. If this really were uncaused creation, any particle one could imagine might pop into existence, the popping wouldn’t satisfy any conservation laws (like charge or lepton number), and so forth. Of course, this doesn’t happen. What does happen is limited by the standard-model Lagrangian. Why? It must be because this Lagrangian reflects the nature of something—a field, a collection of fields, or a medium of which the known particles are oscillations—that actually exists prior to the particle creation and, being its cause, fixes what can even temporarily come into being. Avoiding the metaphysical impossibility of uncaused creation is the very condition for having a sensible interpretation of these or any other physical theories."

    ReplyDelete
  9. The "problem" with an appeal to substantial forms, rhetorically, is that it seems unsatisfying to a scientist trying to find a deeper understanding of the phenomenon. I'm not trying to use the "dormitive virtue" critique (I've read the book!), but just saying "the hydrogen atom behaves in this way because this is just the way hydrogen atoms behave" might tend to close off investigation prematurely.

    Usually, we think we understand a hydrogen atom's behavior by looking at the character of its consituent parts, their states, and interactions, to see if we can understand how the relationships between the components give rise to the behavior in question. And this is not necessarily an attempt to be reductionist - this is an honest attempt to connect our understanding about an entity to an understanding of the behavior of its parts.

    Ed, perhaps you can do a post explaining how a non-reductionist A-T researcher might "correctly" connect explanations of the inner workings of the hydrogen atom to effects produced by the atom due to its substantial form?

    ReplyDelete
  10. Eduardo said...

    Potty... HAS LEFT THE BUILDING!!!
    May 24, 2012 7:00 PM "


    For the moment apparently.

    But before he did so he usefully clarified several matters, and gave strong indications on some others.

    For instance we now know through his own words that "In answer to some Anonymous who wondered why I post here -- it's simple, I like to argue."

    Now, he does claim that that is in furtherance of a dialectical honing and testing of his own ideas. And there might be some truth in that rationalization. But what we also note is that clashing rhetorical swords in comment boxes is not precisely the same thing as seeking out objective truth, if one even admits of such a concept.

    And, I think that we now know that as far as Potty is officially concerned there is no socially non-specific objective truth somewhere available for arbitration when it comes to determining the soundness of evaluative statements, whether moral or otherwise.

    This is not because as logical positivists might have it, that no prescriptive moral statement can be logically derived from a fact description, nor any imperative from an indicative (despite Ayer's later ends-directed hedging); but rather, because in Potty's view values derive their sole legitimacy from categories which have no ontological status distinct or apart from their status as a socially conventional act of categorization employed by some number of categorizers within a given network of associations.

    So, in answer to anonymous' question to Potty: No - as emotionally upset as Potty might personally be by gay-bashing - Potty could not logically or at least consistently say that it was "really" wrong prior to some number of people announcing that it was wrong.

    A parakeet apparently, or certainly a baboon at least, has the same ontological status and hence claim to being *human* as Matthew Shepard did, until such time as someone chose to include Matthew within their circle of concern.

    Short version: Your right to be considered human is like your right to collect social security payments - subject to legislative definition or change, and nothing more is to be said about it.

    It's all a matter of stipulation and the magic power of naming, not of discovery.

    At least that is the gist of and fallout from what Potty has said so far.


    Whether he really believes it, is anyone's guess.

    ReplyDelete
  11. Dr. Feser, it is clear that Dr. Oerter's philosophical writing is homlier than yours. To your credit, you do not seek to take advantage of this, a refraining refreshing to see on the "win"ternet.

    It seems to me, however, that you have missed a point of Oerter's, a
    point not as crisply presented as it might have been.

    Your argument here would be damning if it were simply the case that causality can be left out of the quantum picture. But reading Oerter's arguments several times (I am certainly not a physicist), it becomes clear that he has not leaving causality out. Rather, he says in effect that if we have causality, we have inaccurate observations; we do not have inaccurate observations, therefore we do not have causality.

    As to whether this argument is sound, I do not know, but it is a valid argument.

    So, at this (very early) point in my reading of the various arguments, I am not convinced that Dr. Oerter's conclusion does not follow from his arguments.

    At any rate, thanks to both of you for your delightful exchange of ideas.

    ReplyDelete
  12. "Rather, he says in effect that if we have causality, we have inaccurate observations; we do not have inaccurate observations, therefore we do not have causality."

    You can see the problems with this kind of reasoning through the very comments here. Ed responded to this in part, I believe, by noting that a particular type or instance of causality is what is incompatible with quantum physics. The reply has been to point out that, in the senses relative to the metaphysics Ed is supposing (and to questions of causality in general), that particular type of causality is not the only one available, or the only one thomists rely on.

    The short version is that in all the relevant senses, there are causality-compatible readings of quantum data, just as there are multiple interpretations of the formalism (even Oerter will admit this.) Sure, you can interpret the data of quantum physics in a way that rejects causality. You can also interpret non-quantum data if you so choose. In both cases, there's just no need to do so, and powerful reasons to avoid that move.

    ReplyDelete
  13. Anonymous, firstly I would like to compliment you on your numberless wonderful paintings over the centuries- great work! The obscene telephone calls and tip-offs to the KGB have got to stop, though, shame on you.

    Yes, we could posit "other kinds of cause and effect", but Oerter's argument does not address these mysterious processes. His is an argument which, whether ultimately sound or not, is valid in "the world as we understand it today". This is appropriate for a scientist.

    Those bringing up mysterious varieties of cause and effect proffer their backs to the burden of proof. Please, describe these "other kinds" of cause and effect.

    This is not as difficult for Feser, I think, because the concept of potential actualized is more flexible than that of cause and effect. A potential could conceivably be actualized by an absence, for example.

    ReplyDelete
  14. @DNW

    About his dialectical search. Personally I don't see it. I bet I know how he feels about certain stuff and in this case about Thomism.

    Some things we are open to discuss, and learn more about that, but certain things we are pathiological skeptics, we use any and all excuses to deny arguments or ideas we don't like.

    I bet he doesn't care, there is no need to believe in principles and stick to them for whatever reason, all it matters is that you feel really nice about how you think and feel about the world. I think his morals are just whatever he feels it is moral at that moment, not much different from most people I see, but not rational to any extent.

    Sort of funny the principles you get from what he says huh? Being human is nothing more but a argument of authority or whatever you desire to be human.

    I stil stick to the convenience principle behind this type of thinking... You just start from whatever you believe and create principles or rules so that belief is chosen automatically as the only or the best possible belief. And no need to test your principles, who cares if they don't work XD

    ReplyDelete
  15. "Those bringing up mysterious varieties of cause and effect proffer their backs to the burden of proof. Please, describe these "other kinds" of cause and effect."

    You could try reading Ed's post where he goes into the discussion of what he (and other Thomists) mean when they discuss causality, and what Oerter is limited to discussing as a scientist.

    You could also try looking at the multitude of interpretations of quantum mechanics, and seeing how each of them in turn account for the formality. You'd also do well to realize that interpretations of quantum mechanics are not themselves "science". They are non-scientific interpretations of equations and data.

    Finally, keep in mind that Oerter is describing a kind of "causality" that is singular in science, and in fact antithetical to science (which seeks to describe causes. Oerter is saying that "no cause whatsoever" is an acceptable description.) The evidence he produces is trivially matched and even exceeded: propose any weird idea you want (it was a non-material cause. The universe is a simulation. It was retrocausal/the cause traverses time.)

    I think it's obvious to see why Oerter's objection fails to blunt Ed's arguments, and also why his objection is not scientific, but a pretty old metaphysical claim. It's an interpretation, not an observation, he offers.

    ReplyDelete
  16. Yes, we could posit "other kinds of cause and effect", but Oerter's argument does not address these mysterious processes. His is an argument which, whether ultimately sound or not, is valid in "the world as we understand it today". This is appropriate for a scientist.

    Those bringing up mysterious varieties of cause and effect proffer their backs to the burden of proof. Please, describe these "other kinds" of cause and effect.

    This is not as difficult for Feser, I think, because the concept of potential actualized is more flexible than that of cause and effect. A potential could conceivably be actualized by an absence, for example.


    None of us are QM specialists, but I'd imagine that some would propose non-local hidden variable theories. For all of its problems, the De Broglie-Bohm interpretation seems vastly preferable to the metaphysically ignorant "uncaused" versions of Copenhagen.

    In any case, you are right that act/potency can easily be applied to QM. Far more easily, in fact, than a mechanistic conception of cause and effect.

    ReplyDelete
  17. goddinpotty said... It's difficult to say what that something else is

    It's very easy to say: it's Christianity. And, slowly but surely, it "expands the circle of empathy" because it defines an essence for being human, which doesn't depend on your sex or skin color or so on. It does therefore also define what it is to be a good human or a bad human, but people don't like being told that certain behaviors are intrinsically wrong (or even extrinsically wrong), which is why its progress is slower than it could be. But truth will out.

    ReplyDelete
  18. @rank sophist:

    "None of us are QM specialists, but I'd imagine that some would propose non-local hidden variable theories."

    This is not the only option. The Bell inequalities (That Prof. Oerter so much enjoys invoking) are actually a red herring as explained by Prof. Feser, but for some reason, some people just don't get it, so let me take a stab at it from the physics angle. First, the proof of Bell's inequalities has some hypothesis. Hypothesis are loopholes. For example, we could deny conterfactual definiteness and appeal to superdeterminism. But since, to borrow from a gentleman that will go unnamed, I believe that people who deny Free Will are either stupid, wicked or insane (more probably, a combination of all three), that is not a road I want to pursue.

    We can also jettison Boolean logic. And by this I do not mean embracing the quantum logic of Birkhoff and Von-Neumann. As far as I know not much has come from that corner of the world and there are even good reasons to doubt that quantum logic qualifies as a logic given the several negative results, starting with those of Jauch and Piron, lack of distributivity, the difficulties in defining an implication operator, etc. (although Pavicic, Megill and some others have argued otherwise). What I am talking about here is weakening classical Boolean logic to intuitionistic logic. We do *not* have to accept the intuitionist philosophical baggage along with it and instead adopt a practical stance: we are simply introducing a finer-grained distinction for statements, that of being provably true and constructively, provably true and reinterpret the logical connectives along this axis. The adverb "constructively" meshes well with how we understand physical theories. After all, their job is to correctly predict the measured correlations in experiments, so they have to take into account, directly or indirectly, the limitations of the measurement process. And this is where the program of C. Isham and collaborators comes in; they take ideas from topos theory (a topos is a universe of mathematical discourse but whose internal logic is intuitionistic. Standard ZFC gives a Boolean topos) to construct types of physical theories. If anyone is interested, What is a thing? is a starting point. And why is C. Isham tackling the foundations of QM? Because he is interested in Quantum Gravity, and if you want to do QG, the standard Copenhagen interpretation of QM *must* be tossed out because, among other things, no sense can be made of an observer external to the universe. Will it pan out? Only time will tell. Either way, I am not a physicist so I am not competent to judge.

    ReplyDelete
  19. @rank sophist (continued):

    Rejecting the above two paths in my previous post (for whatever reasons), can we make sense of Bell's theorem? There are at least three ways to rationalize its conclusions while keeping a realist interpretation:

    1. Non-local causes: this is the route you mentioned. It keeps the possibility of science and rationality intact and in fact I have a lot of sympathy for it. For if Quantum Mechanics is telling an approximately correct picture of reality then non-locality is just about inevitable. In CI it is located in the state vectors that are inherently non-local (straightforward consequence of Heisenberg's principle). CI salvages the mess by stating that state vectors are not directly observable and are something like a purely theoretical construct. Of course the lump was just shifted to a different place and it reappears in "spooky action at a distance" phenomena. The problem with non-local variables is that it opens a *nasty* can of worms and does not bode well for the intelligibility of the universe.

    I should add that there are other causal, purely deterministic interpretations of QM, but either they are completely mad (many-worlds interpretation) or I do not understand them (Ahoronov's time symmetric theories). And there are interpretations that are agnostic on the issue (M. Born's ensemble interpretation and consistent histories). Not *one* of the traffickers in uncaused events has bothered to explain why we should prefer one interpretation to any other, especially when the empirical data cannot decide the matter. So what are they appealing to? Their own ignorance?

    We can also:

    2. Posit a non-natural cause, like God.

    This is occasionalism in disguise and a hard pill to swallow for both atheists and Thomists.

    3. Posit a cause that cannot be described in mathematical terms, meaning it cannot be described as a random sample drawn from a probability space with a well-defined probability and expectation value. The cause in question could still be local, natural and real, but just not describable by mathematical formalisms, and concomitantly by the empirical sciences. Something like a "nature that actualizes its perfection" -- that Aquinas dude was onto something.

    I can already imagine the indignant response to 3. Something like "Hey you are cheating!" by appealing to non-measurable causes, and thus not amenable to scientific treatment. But pray, someone enlighten me how is it different from the *blatant* cheating in assuming an equally non-empirically falsifiable absence of causes? What is good for the goose is good for the gander and all that. Not that the peddlers in uncaused events have deigned to define causality writ large for us; they can hardly say what it is, but by God they know it is violated. But this just highlights the main lesson of this discussion. The debate is ultimately metaphysical; it is not that input from the hard empirical sciences is irrelevant to it, is that it *alone* cannot decide the issue, not even in principle.

    ReplyDelete
  20. "standard ZFC gives a Boolean topos) to construct types of physical theories. If anyone is interested, *What is a thing?* is a starting point. And why is C. Isham tackling the foundations of QM? Because ..."


    Huh ... I was tempted to make a crack invoking the name of Heidegger, and thought better of it, clicking the link instead ...

    ReplyDelete
  21. @grodrigues,
    purely as a formality, I would like to lodge the anticipated objection against unmeasurable causes.

    My reason is as follows :
    if I admit of an unmeasurable cause to a measurable effect then the function from cause to effect must also be unmeasurable.

    This would mean that if I asked the question "why do I think that A caused B, and not something else" I could not expect an answer. Since a deduction from A to B would induce a measurable function.

    We hold the idea of causality because it helps us make sense of the world. A cause that makes no sense is no cause at all.

    Thank you for the link to the quantum topos logic work. I will never have the time to read it, but it is nice to know that it exists.

    ReplyDelete
  22. grodrigues,

    I appreciate your massive posts, but a lot of the information went over my head. However, I get the general picture: there are countless options, most of which aren't empirically more likely than the others. Uncaused-Copenhagen is an unargued assumption.

    if I admit of an unmeasurable cause to a measurable effect then the function from cause to effect must also be unmeasurable.

    This would mean that if I asked the question "why do I think that A caused B, and not something else" I could not expect an answer. Since a deduction from A to B would induce a measurable function.


    This does not apply under Aristotelian logic. Final causality (directedness) is not measurable nor explicable by empirical science, and yet it can be used in "A causes B" formulations. Consider this recent example: http://www.thepublicdiscourse.com/2012/04/5119. You can measure the effect of the directedness, but not the directedness itself.

    ReplyDelete
  23. Yes, you did. No one else in this conversation was talking about it whatsoever, but you suddenly blurted it out unprovoked. It says a lot.

    Calls to mind the old saying, "Heresy begins below the belt."

    ReplyDelete
  24. Pardon my ignorance, because this is a very basic question on causality.

    If the universe (as in space-time) began to exist, then there was no "time" before time's existence. I find this hard to comprehend: how can time have a beginning whereas "beginning" presupposes the existence of time. I mean, how can anything happen "outside" time? It seems logically incomprehensible. Any act (whether doing something physical or just "thinking") seems to be in the confines of "time".

    And if there is no time before the existence of time, then can it be the reason the universe doesn't need a cause?

    ReplyDelete
  25. " I find this hard to comprehend: how can time have a beginning whereas "beginning" presupposes the existence of time."

    Well if time or space-time was formed at the Big Bang that you had indeed a beginning of time itself.

    Let's say, you have a rod. The rod has a beginning and an end or at least extremities. It is futile to speak of the rod outside the rod, there there is no rod.

    Time can in theory be treated as any dimention, and it does not have to be infinite at any one of its ends.

    " I mean, how can anything happen "outside" time? It seems logically incomprehensible."

    That is only if you interpret as something happening as something that happens in time with accidental causes that follow in time.

    Althouh it is hard to imagine, there can be events ans causes outside of time, even some physicists claim that.

    Some physicists claim even that time is just an illusion and does not exist.

    This is of course very abstract.

    I mean yo ualso have mathematics in INFINITE DIMENSIONS. You can have "spheres" with 34 dimensions(instead of 3) and calculate their 'hypervolume' in 34-D and their "hypersurface" in 33-D.

    Try to visualize a sphere in just 4 dimensions... impossible. Yet you can conceive it mathematically.

    Some very abstract things we can't just visualize or 'imagine' but we can reason about.

    You do not even have to go as far as weird mathematical entities:
    the very Quantum Mechanics core is hard to picture or imagine!

    Imagine an electron? What is it? Not a particle. Not a wave... something in between we cannto fathom.

    ----


    "And if there is no time before the existence of time, then can it be the reason the universe doesn't need a cause?"

    As said not all acts and causes need to be inside time.

    Also if time began to exist at some point there must be a cause. It would be actually irrational to think otherwise.

    ReplyDelete
  26. I think the main failure of Oerter is to fail to distinguish between 'causality' and 'determinism'.

    The hidden-variable problem he talks about regards NOT causality, but indeed the stochastic nature of QM, rather than the deterministic nature we know from classical mechanics.


    HERE indeed is Oerter's flaw:
    Let's suppose that there is some physical property - something not included in the quantum mechanical description - that determines for each atom exactly when the electron will decay.

    Here the problem is NOT causality, but DETERMINISM.

    Those are two very different things.


    Oerter is also assuming that the only causes that exist are 'efficient causes' and perhaps he goes beyond, that the only causes are 'deterministic causes'.

    That is like saying:
    "the only way to tavel from New York to Paris is by car (or bike).
    Since you cannot go to Paris from NY by car, cars do not exist".



    The very fact is that electrons or other onjects at a quantum level DO follow a set of rules,

    EG: Take an electron excited by e photon that then decays emitting a photon. A typical 'pump-probe' experiment with a laser excitinbg a sample and measuring it's fluorescence.

    Sure the time when ONE electron decays is indeterminate, but if you take 1 trillion electrons, they will all decay with the same pattern, like an exponential function with a defined 'half time'.

    The fact is that if I do a pump probe experiment on the same molecule, I will obtain always the same result.

    The very fact that repeating such experiments on the very same system reproduces always the very same exponential function (forgetting about noise and changes in the system due to the influence of the measurement itself) indicates that the elctrons DO follow some 'rules' when decaying.

    indeed the decay half time indicates a CAUSE. An ensemble of electrons when measuring an ensemble of molecules(ie liquid benzene) will decay differently than another molecule or in different conditions (eg aniline or pentacene or benzene mixed with some non-fluorescent apolar solvent)


    This does not mean such causes or rules requires 'determinism', nor do they entail that QM is 'incompletete' or we need to invoke 'hidden variables'.


    So the problem has never been causality in QM (unless you think only of deterministic efficient causes) but determinism!

    ReplyDelete
  27. I think ANY phisicists who interprets Quantum Mechanics correctly will disagree with Oerter.

    Unfortunately DOING QM is very different than INTERPRETING QM. I do NOT mean interpretation of the experiments to get the results (i.e. a given energy) but rather understanding QM at a fundamental level.

    Most textbooks (and I mean graduate level text books, not some pop-science book) do NOT take a anti-causality approach, also they affirm that 'understanding QM' is impossible, we can only 'DO' QM (ie. calculations and experiments). Although if really understanding QM is impossible or not is debatable and there are many interpretations of QM.


    I mean pick up for example (these are undergraduate-graduate level textbooks, some of the best IMO):

    Greiner - "Quantum mechanics. An introduction"

    or

    Griffiths - "Introduction to Quantum Mechanics"


    and read the last chapters (althoug I recomend reading the first chapters that give the theoretical and mathematical basis first!) and you'll see what I mean.

    ReplyDelete
  28. You're missing the point with the Bell's theorem objection. Oerter is not inferring from the premise "QM describes such-and-such a state without describing its cause"  to "QM shows that such-and-such a state has no cause". He is inferring the latter statement from Bell's Theorem, which proves that there cannot be a hidden cause of quantum mechanical events (under certain assumptions, as he says). For all that you accuse your opponents of misrepresenting you (usually due to wording that is seemingly intentionally vague), you're making a total strawman here.

    ReplyDelete