Mental vs. Top-down Causation: Sic et Non
Dr. J.P. Moreland argues that top-down causation has little evidence, and furthermore it is not necessary for mental causation. He defends the reality of mental causation as a properly basic belief.
Well, welcome brothers and sisters. Good to have you with us. You should have a copy of the paper so would you please follow along as I read. Many think the top-down causation is essential for preserving the causal efficacy of the mental. Thus, Nancy Murphy claims the top-down causation is crucial for avoiding causal reduction and accordingly, leaving room for mental causation and responsible agency.
Now it seems to me that the causal efficacy of the self, and it’s various mental states is correct. Indeed, I believe that this is a properly basic belief grounded into feasible knowledge by acquaintance with the self’s and it’s mental states causal activities. But I’m not so sanguine about top-down causation, at least when it is located against a certain metaphysical framework, to be mentioned below. When properly interpreted I don’t believe that there are any clear examples of it and I think that there’s a persuasive case against top-down causation. In order to clarify and defend these claims, I shall first lay out two preliminary considerations relevant to what follows. Second, show why I don’t believe alleged examples of top-down causation are convincing in a way that is pertinent to mental causation.
Third, present a case for why there is no top-down mental causation. And fourth, suggest an important option for moving forward and preserving what we all know to be the case, that mental causation is real. Two preliminary areas of clarification and causal powers. In this article, I shall assume a causal powers view of causation, according to which the essence of causation is causal production, the bringing about of an effect by an exercise of active power or by the triggering of a passive liability. In the causal powers view, causation cannot be reduced to noncausal notions, to supervenience.
There are three different kinds of properties that are involved and three different types of supervenience. The first is a functional property. F is a functional property, means F is functional concept that is constituted by role R. Moreover, F supervenes on sum entity E, if and only E plays or realizes role R. In my view, Jaegwon Kim has argued persuasively that there are no functional properties that characterize things in the mind-independent world. Rather, functional properties are functional concepts, ways of describing or taking something for certain purposes. For example, the certain piece of paper exemplifies being rectangular, but it realizes the functional concept of being a dollar bill. One virtue of Kim’s approach is that it simplifies our ontology when compared to a more abundant view of properties. On an abundant view, a dollar bill actually has the property of being a dollar bill that, in turn, could be identified with the property of being such as the play role R.
And in the right circumstances, people would also take people of paper to play role R by having the concept of playing role R. Kim’s approach simplifies our ontology by reducing the property of being a dollar bill to the concept of playing role R, and this is one reason I prefer to go with Kim here. Given his view, Kim has offered the causal inheritance principle that entails the epiphenomenal nature of functional properties when compared to their realizers. If a second order functional property F is realized on a given occasion by a first-order property H, then the causal powers of this particular instance of F are identical with or a subset of the causal powers of H, or of this instance of H. The causal powers of a functional property just are those of its realizer, and a causal description is actually epiphenomenal.
It does not carve the world at the joints, nor does it correctly ascribe a unique, new causal power to an entity that it didn’t already have independently of that causal description. Thus, since we are interested in attempts to preserve distinctively mental causation, functional properties will not be a focus in what follows. To understand the other two kinds of properties, it will be helpful to clarify a distinction between emergent and structural properties in supervenience.
An emergent property is a completely unique, new kind of property, different from those that characterize its subvenient base. Accordingly, emergent supervenience is the view that the supervenient property is a Mariological symbol intrinsically characterizable, novel property different from, and not composed of the parts, properties, relations, and events at the subvenient level.
We may clarify the sense in which emergent properties are novel as follows. Property P is a novel emergent property of some particular X at level Ls of N, just in case P is an emergent property. X exemplifies P and there are no determinants P prime of the same determinable D as P, such that some particular levels lower than N exemplify P or P prime. By contrast, a structural property is one that is constituted by the parts, properties, relations, and events at the subvenient level. A structural property is identical to the configurational pattern among the subvenient entities. It is not a new kind of property. It is a new pattern, a new configuration of subvenient entities, and many philosophers would characterize emergent and structural supervenience as causal and constitutive, respectively. Since I am contrasting emergent and structural supervenient properties, I will use the notion of an emergent property as a simple novel sui generis property. Top-down causation.
There is a ubiquitously presented argument for top-down causation among those who accept both a standard presentation of the mariological hierarchy and various subvenient properties at levels above the microphysical. Here’s the argument. Throughout the natural world, there are numerous examples of emergent properties that exhibit top-down causation and this fact establishes a context and plausibility structure for justifying the belief in and understanding mental causation, so mental causation is assimilated to these other kinds of top-down causation.
In reply, I shall argue that the analogy between the mental case and the others is a poor one, and thus, even if we accept the reality of the other examples, that provides no evidence for mental top-down causation. To understand and evaluate this dialectic, we need to get clear on two things. The mariological hierarchy and the actual nature of top-down causation. The hierarchy. Let us construe the mariological hierarchy ontologically and stipulate that there is, in fact, a basic level, which is the micro physical tier of atomic simples. Three things are important about the hierarchy.
First, there is an othological dependency relation between levels N plus one and N with the former superveniening on and being grounded in the latter, terminating with the bedrock micro physical level. Everything is dependent on and determined by the micro physical and micro physical process are causally closed to efficient causal intervention from higher levels. Second, in the category of individual, ontological reduction is accepted in the sense that there are no nonphysical particulars, souls and telekeys and so forth, in that category. The relation between entities at level N and those at N plus one is the separable part whole relation. More overall, particulars above the level of microphysics are mariological aggregates, systems of parts standing at various instantiations of structural relations.
Here’s a characterization of a mariological aggregate. It is a particular whole that is constituted by at least separable parts and external relation instances between and among those separable parts. There is a debate as to whether or not one should add an additional constituent vis a surface or a boundary to the analysis. The third important feature of the hierarchy is the existence and nature of emergent properties. The first two piece features of the hierarchy would be accepted by my dialectical opponents and me.
However, from my reading of this literature, the main advocates of the view I am criticizing, see below, fail to distinguish structural and emergent supervenience and accordingly, merge both kinds of supervenience under the category of emergent properties. But as we will see below, this is a serious mistake. In the category of property, virtually all the properties above the level of micro physics are structural and not emergent properties.
To illustrate my charge, in his wildly referenced work, The Emergence of Everything, Harold Morowitz cites 28 examples of emergence, for example, the emergence of stars from collections of primordial matter, the emergence of chemical elements from a combination of more elementary particles, the emergence of new cell structures in the evolution of eucaryotes from procaryotes, and all of them except the emergence of thought or spirit are cases of structural emergence.
Philip Clayton claims that in the process of evolution, we regularly see complex new kinds of combinatorial novelty. Clayton lists numerous examples of emergence and as far as I can tell, every one of them is structural, not emergent, with the main exception being that of consciousness, which he treats as a genuinely emergent property, as I characterized it above. Nancy Murphy uses these locutions to describe emergent properties. They exhibit a new sort of organization, a larger pattern or system of causal powers at the new level, a unique set of relational properties composed of the system’s constituents. And when Murphy and Warren Brown categorized different types of emergent properties, all of them are structural in nature. At this point, I’d like to make two observations.
First, given the higher level properties are structural, it is hard to resist the notion that they are decomposable into the micro physical level except for exhibiting new relation instances. And the same is true of the mariological aggregates in the category of individual. Accordingly, Andrew Bailey calls structural supervenient properties group level properties, and says, quote “it makes some intuitive sense “to continue thinking of group level properties “as being at a higher level than the properties “of their components, but in fact, “they’re really just very complex concatenations “of so-called bottom level properties.”
Moreover, the pattern of top-down causation is established with reference to numerous examples of structurally supervenient properties, but as we shall see below, if consciousness is emergent, then the analogy between the former and the latter is not a good one in this sense. Even if, in some way or another, structural properties exhibit top-down causation, it doesn’t immediately follow that emergent properties do. Given that the mental is emergent, more work needs to be done to establish mental causation besides citing examples of structural supervenience. To the real nature of top-down causation.
Two aspects of top-down causation are important for my purposes, the direction and precise function of such causality. Let’s begin by focusing on the direction of top-down causation. In this regard, Philip Clayton says that top-down causation is quote “the process whereby some whole “has an additive active causal influence “on its parts.” Clayton’s ontological characterization may fairly be taken as canonical, such that top-down causation is widely depicted as moving from parts to whole. The main problem with calling whole, from whole to parts, sorry.
The main problem with calling whole to parts causation top down is that it’s not top down. It’s outside in. The mariological hierarchy doesn’t go up. It goes out. From micro physical particles to atoms, to molecules, cells, organisms, ecosystems, and so on, the movement is towards wider and wider configurational patterns at the same level of reality. Thus, all the examples of structural supervenience are not examples of genuine top-down causation, but of outside in causation. For example, in illustrating top-down causation, Helen Stuart advances the frequently used molecule in a wheel case.
When force is applied to a molecule outside a wheel, that’s on its own, it will travel along a certain path, but if it’s part of a rolling wheel, it’s path will be determined in a quote “top-down way” by the wheel of which its a part. Now, it should be clear that a wheel structurally supervenes on a collection of subvenient parts and this is an example of outside in, not genuine top-down causation, where the wider context constrains the movements of a particular atom in the wheel. It is crucial to keep in mind that examples of structural supervenience are cases of outside in and not top-down causation because if there really are casually efficacious and emergent properties, their causal activities would indeed be examples of top-down causation. Why?
Because the instantiation of an emergent property is a state of affairs whose coming to be and continue to existence in nature are either efficiently caused by or at a minimum, ontologically dependent on and determined by the lower level. Such emergent properties rest on top of the subvenient entities that sustain them. And if they are to exhibit causal power, it must be from the emergent to the subvenient level by intervening in the chain of events at that level. It is important to note that the disanalogy between outside in versus top-down causation means that piling up more and more examples of the former does not in the least show that the latter is possible. The distinction between outside in causation between a mariological whole and its parts, on the one hand, and top-down causation between a simple emergent property and its subvenient base, on the other hand, is an important one.
Those who think the mariological hierarchy goes up levels, such that individuals or supervenient properties at higher levels rest on top of and exert top-down causation with respect to individuals or subvenient properties at lower levels fail to make this distinction. Moreover, they fail to distinguish two different disanalogous ways that higher level entities are ontologically dependent on lower one. One, mariological wholes and structurally supervenient properties are relational structures that are dependent on certain parts because they’re composed of those parts. By contrast, an emergent supervenient property is a mariologically simple quality that is dependent on its subvenient base because the base brings the quality about and sustains it in existence without composing it. So much for the direction of causality. Regarding the precise function of top-down causality, there is a view, according to which, wholes exert efficient causality on their parts by intervening into the chain of subvenient events and changing the direction of that chain. In this sense, top-down efficient causation involves causal activities that quote push and pull the lower level components of the system.
As far as I can tell, this view is universally rejected by the advocates of top-down causation I’m seeking to criticize. Nancy Murphy argues that such a notion of top-down causation may require the postulation of spooky new entities. It threatens the integrity of the special sciences and it smacks of interventionism, according to which, wholes intervene in the course of the micro physical processes and, as it were, interrupt them. Helen Stuart opines that this notion of causation is spooky, magical, dualistic. It doesn’t get any worse than that. And, otherwise, problematic. Now, I’m feeling really bad about myself right now. Gee. [laughter] In light of these remarks by Murphy and Stuart, an alternative view of top-down causation is offered.
Top-down causation for structurally supervenient properties should be cashed out, not in terms of efficient causality, but in terms of causal constraints. Various distributions of the whole’s parts are consistent with micro physical laws, but that one distribution was selected as opposed to another must be explained by referring to quote “higher level entities”. Thus, top-down causation functions as a larger system of causal powers having a selective effect on lower level entities and processes.
Further, higher level entities, wholes, processes, relational configurations, provide context sensitive restraints, for example, boundary conditions, feedback loops, non-linear factors on the parts at lower levels. And higher level entities are what sustain the sequence of synchronous arrangements of subvenient parts, for example, reference to a whirlpool and its top-down causal influence must be made if we are to explain the relatively stable sequencing through time of subvenient parts arranged whirlpooly.
By contrast with the view just presented, if we grant a causal powers view and a rejection of causal overdetermination, a genuinely emergent property with causal efficacy will exert top-down causation in such a way that physical causal closure is violated and the exercise of causal power by the emergent property changes the flow of events at the subvenient level. It’s time to summarize what we’ve learned in this section. The mariological system of reality depicts all levels as dependent on micro physics, in that the laws governing that level or not gappy with outside intervention. The hierarchy goes out, not up, and accordingly, complex individuals or mariological aggregates with structurally supervenient properties that exhibit outside in causal constraints and selection on their parts.
While acknowledging a disanalogy between emergent properties and other emergent properties, mental and other emergent properties, Philip Clayton nevertheless asserts that quote “understanding the relationship “between mind and brain, “between consciousness and its neural correlates, “requires understanding the multi-leveled structure “of the natural world.” On this view, the appearance of mental causes is in one sense just another case of emergence, just another case in which a complicated natural system gives rise to unexpected causal patterns and properties. As I’ve already suggested, nothing could be further from the truth. Other examples of supervenience are structural.
Conscious properties are alleged to be emergent. Other examples involve outside in causation. Conscious properties involve top-down causation. Other examples exhibit selective constraining causal influence. Conscious properties exhibit efficient intervention as causality. Mental causation as top-down causation. Is there a positive case against the top-down causal efficacy of emergent mental properties? I believe there is. And before we examine it, let us look at the dialectical context. For the sake of argument, let us grant that mental and value properties are emergent.
And let us also grant that secondary qualities are emergent categorical properties that objectively categorize mind-independent entities. So far as I can tell, given the mariological hierarchy, these are the only examples of genuine emergent properties. Now it seems that secondary qualities and value properties are epiphenominal. Their exemplification by an object either does not bestow any causal powers on that object or those powers are never actualized. In the other two cases of emergent, if the other two cases of emergent properties are epiphenomial, secondary qualities value properties, this fact would seem to place the substantial burden of proof on those arguing for causal efficacy of mental properties construed as emergent.
So far as I can tell, mental properties provide the only case of emergent properties that can plausibly be taken in to exert genuine top-down causation. In this regard, it is important to note that in the best current defense of genuine top-down causation regarding emergent properties, a Tim O’Connor and Churchill acknowledge that the only clear candidates for such causation are emergent mental properties. The positive argument against top-down causation I have in mind is one that appropriates certain insights from A General Case Against Such Causation by Jaegwon Kim.
Kim’s supervenience argument, also called the exclusion argument, purportedly shows that, given the reducibility of the mental, they can be not mental causation in a world that is fundamentally physical as depicted by the mariological hierarchy. And, according to Kim, this raises serious problems regarding cognition and agency, two features of our lives that are hard to give up. The supervenience argument, says Kim, may be construed to show that mental causation is inconsistent with the conjunction of four thesis, closure, exclusion, that is no overdetermination, supervenience into mental irreducibility. Now, this argument is has been widely discussed, but what have garnered less attention are certain background issues Kim advances prior to formulating this supervenience argument.
According to Kim, the fundamental idea behind the argument is what he calls Edward’s dictum. Vertical determination excludes horizontal causation. In support of the dictum, Kim invites us to consider a lump of bronze whose macro properties, such as color, density, or shape, are dependent are and determined by its synchronous micro structure. Now, suppose the lump is yellow at time T. Why is this the case? Two answers are possible. One, its micro structure at T causes the color to emerge. Or two, it was yellow at T minus delta T. Unfortunately, says Kim, there is a tension between these two, such that there is neither need nor room for the second explanation. I would add that this seems especially correct given a causal powers view of causation. In a lengthier version of the paper, I deal with the problem of causal overdetermination that has been advanced by Sider, but he doesn’t really take into account a causal powers view of causation.
He takes other views into account and I’m assuming a causal powers view. The lump at T would be yellow given its micro structure no matter what was the case at T minus delta T. Kim advances a second illustration, taken from Johnathon Edwards. The success of images of an object and a glass do not remain the same, nor do earlier images cause later ones. Rather, each successive image is caused by, and the series of images is constantly renewed with respect to a sequence of new light rays that bring about each image.
Again, there is neither need nor room for each image to cause its successor or to exert top-down causation. In the argument to follow, I will be employing Edward’s dictum and two cases used to illustrate it in my arguments against top-down emergent property causation. And we will be considering situations in which a mental property emergently supervenes on a subvenient physical base. Some might think that these supervenient situations are not analogous with the second case, that it, the glass image case above. Why? Well, of the two cases, the latter one, the glass image case, is a case of efficient causality and the former one, the bronze color case, is a case of synchronous supervenience. And the objection continues.
Efficient causality is just different from emergent supervenience, so the glass image case is not relevantly analogous with the emergent, cases of emergent supervenience. Now, some take synchronous supervenience to be an example of efficient causality. In fact, that is my own view, But even if we don’t agree with this opinion, the glass image case is still relevantly analogous with the emergent supervenience situations because both sorts of cases, efficient causality and the relation between cause and effect, emergent supervenience and the relation between emergent and subvenient properties, and evolve an ontological dependence and determination of one entity on another, diachronically or synchronically, and I believe it will become evident below that this is the important analogous feature between the two cases for my purposes.
Note that Edward’s dictum and the two supporting illustrations are not defeated by the truth of causal powers view of causation and properties. For example, even if the instantiation of secondary qualities brings about their individuating causal powers. Those powers are preempted and never actualized. Moreover, given a rejection of overdetermination, it is important to see that in both of these cases, top-down causation is eliminated without a fundamental commitment to the causal closure of the physical, a commitment I do not embrace.
It is emergence as depicted in the mariological hierarchy that does the trick along with the fact that we have a pretty good micro physical story, depicting sequence of changes at that level as a causal chain. Instantiations of properties at the emergent level are completely dependent on and determined by instantiations of properties at the micro level. Changes at the emergent level are due to changes at the micro level.
Given emergent dependence, the emergence level becomes a series of epiphenominal states synchronously dependent on the micro level. The achronic causation at the emergent level is preempted and given that there is causal chain at the micro level, there is neither need nor room for top-down causation. In light of Kim’s background considerations just mentioned, it would seem that the culprit, regarding top-down causation, is emergence.
Granting the mariological hierarchy’s twin commitments to the micro physical level being basic and to genuinely emergent properties, these properties, or rather, their instantiations seem to be a series of epiphenominal states. This surely appears to be the case with secondary qualities and value properties and would be odd to say the least to make an exception in the case of mental properties. Even if the instantiation of these three sorts of properties bring along their causal powers, that doesn’t seem to be, there doesn’t seem to be need or room for their exercise. O’Connor and Churchill advance the following Kim style argument against non-reductive physicalism, by the way, what I mean by that, is functionalism. That is important for our discussion.
First, causal non-reductionism, that’s the idea that causation is real, is real, irreducible relation. A production account of causation, causation consists in the exercise of causal powers and a causal theory of properties. Properties are individuated with respect to their causal powers. One to three unpack a causal powers ontology, according to which causality is irreducibly real, it consists in the production of an effect, and causal powers are part of the identity conditions for other properties. Four, the supervenience thesis. Mental properties strongly supervene on physical properties. Five, the realization thesis. Mental properties are realized by physical properties. Six, completeness, causal closure of physics.
Different ways of stating that, but basic idea they state is every physical event that has a cause has a completely physical cause. Four to six unpack non reductive physicalism in which mental properties are either functionally or structurally supervenient. One to six are inconsistent with seven. Seven, a mental property M is distinct from its physical realizer property P and each event that consists of M’s being instantiated exercises a distinct form of causality that in one way of another, impinges on the realm of physical events, assumption for reductio.
Eight, the instantiation of M either directly produces a subsequent mental event, M star, so that would be top-top causation, or it directly produces a wholly physical event, P star, that would be top-down. The realization thesis and the causal production thesis seem to rule out Eight A, because they jointly imply that M has to cause P star on which M star is ontologically dependent. M cannot directly cause M star, so not Eight A.
Six, the closure of the physical implies 10, if Eight B, that is if M produces P star, then the physical event P star is overdetermined by M and some other physical event, which would be P, on which M depends. Now, P star can be counterfactually dependent on M and P, but since we are assuming a causal production view of causation, there is no need or room for M in light of P, and so we get there is not systematic mental physical overdetermination as the consequence of 10 implies. 11 and the consequent of 10 imply not Eight B by modus tollens.
Therefore, 12, M does not make a distinctive contribution to occurrences in the physical world, whether wholly physical or supervening mental occurrences. O’Connor and Churchill conclude by claiming that since three of the causal theory of properties rules out epiphenomenalism, we should either identify M with P or just deny that M is a genuine property, so go the reductionist or limitivist line. Now, I believe this argument is successful against non-reductive physicalism, but my purpose is presenting the argument is not to evaluate it on that score. Rather, I want to adjust the argument and try to show that the adjusted version is successful against the causal efficacy of emergent property dualism.
Let’s begin with a few observations. First, as far as I can tell, the argument does not make or at least require explicit use of the supervenience thesis. In 12, the phrase “supervening mental occurrences” could as well have been realizable mental occurrences. And the argument’s move from Eight to Nine employs realization, not supervenience. In my view, realization is sufficient to go from eight to nine, but it’s not necessary. Our investigation of Edward’s dictum above suggested that supervenience, especially emergent supervenience alone, without the need to appeal to closure, will justify the move from eight to nine.
Problem with the causal efficacy of an instantiation of an emergent property is that it is a state of affairs totally dependent on and determined by its subvenient base. But what about O’Connor and Churchill’s claim that three, the causal theory of properties, which is the idea that when a property is instantiated, it brings along its causal powers with it, and they constitute some of the identity conditions for those properties. But what about causal, O’Connor and Churchill’s claim that three, the causal theory of properties rules out epiphenomenalism?
Well, if that were the case, I think it would count against three. Why? Because we have strong intuitions that there is a relevant possible world in which epiphenomenalism is true, a world in which a mental property’s causal powers are not, and perhaps cannot be exercised, even though they’re present. In such a world, those powers are real but preempted. Remember, it’s not enough to avoid epiphenomenalism that an instantiated emergent property has causal powers. Those powers must be capable of being actualized, and if for some reason or another, such as Edward’s dictum and the two supporting illustrations cited above, that can’t happen, we have both three, a causal powers view, and epiphenominalism.
Thus, I think their premise seven should be replaced with seven prime. I’ve italicized my changes to seven. A mental property M is distinct from its physical and I used supervenient property instead of realizer, P, and each event that consists of M’s being instantiated has to per sake capacity to exercise a distinctive form of causality that one way or another impenges on the realm of physical events. According to seven prime, a causal theory of properties means that the instantiation of the mental property carries with it the capacity for M’s unique causal powers to be exercised, a capacity that could be blocked or preempted by other factors.
In light of these observations, I believe a causal powers Kim style argument can be developed against the causal efficacy of emergent mental properties along the lines of the O’Connor Churchill argument. The argument accepts premises one to four. That’s the causal powers view and supervenience, sets aside five, the realization thesis, and six, closure, uses seven prime instead of seven. It also involves stating a new premise and P for the purposes of reductio. So, here’s the argument. One to three is before, a causal powers view of properties and causation. Four prime, the conjunction of the supervenience thesis and the mariological hierarchy’s depiction of the micro physical level as basic and its sequence of events as a causal sequence.
Seven prime, a mental property M is distinct from its physical subvenient property P, and each event that consists of M’s being instantiated has the per sake capacity to exercise the distinctive form of causality that, one way or another, impinges on the realm of physical events. New premise. An instance of M makes a distinctive contribution to occurrences in the physical world, whether wholly physical or supervening mental occurrences. What M P does is bring seven prime from potency to actuality. Four, the supervenience and mariological hierarchy thesis and two, the causal production thesis, seem to rule out eight A. So, not eight A. Ten, if eight B, then the physical even P star is overdetermined by M and some other physical event. Assuming a causal production view of causation in four prime, there is no need or room for M’s causal activity in light of P, so we get there is not systematic mental to physical overdetermination as the consequence of 10 implies.
So, we conclude that not eight B and generally, 12 in instance of M does not make a distinctive contribution to occurrences in the physical world, whether wholly physical or supervening mental occurrences. 12 is inconsistent with M P, and thus, 12 completes our reductio. Epiphenomenalism follows for all possible roles in which mental property satisfy four prime, and this is consistent with the causal theory of properties. In this possible worlds, mental properties are, as it were, bring their defining mental powers along with them. It’s just that emergent supervenience in the mariological hierarchy preempt their actualization, a way forward.
My arguments against the causal efficacy of emergent, especially mental properties, have not appealed to the physical, to physical causal closure. In my view, closure is not basic. It follows from emergence and the standard mariological hierarchy. As I mentioned in this article’s introduction, belief in the selfs and its mental state’s causal efficacy is properly basic. Almost all of us know this efficacy is true. So where do we go from here?
You’ll be shocked to find out that substance dualism is the way out. [laughter] From what we have seen, the problem resides in treating mental properties as emergent ones against the backdrop of the standard mariological hierarchy. I believe this standpoint should be rejected with regard for providing an ontological analysis of causally efficacious mental subjects. Indeed, I think that some form of substance dualism would provide a way out, but arguing for that alternative must be left for a different occasion. Thank you. [applause]
Do you see I brought a bible up here with me? [laughter] But I did forget to bring up the microphone. When I first read JP’s paper, I was saying yes and amen over and over again. Then I realized that if I just said this, I would not be a very helpful commentator. So, I decided to think more critically about it, and after careful thought, eventually came to the realization that I disagreed with the way the issue is framed by participants in the debate, a framing that Moreland assumes in his critique. In particular, I tried to, because I have a physics background, I tried to put this whole talk into what’s actually going on physically, and I had a lot of trouble doing it. Making sense of this talk about top-down causation, structural properties. It didn’t seem to comport with what I know of the physical situation.
So, that’s really what’s going on here for me. To begin, consider Moreland’s definition of a structural property as one that is constituted by the parts, properties, relations, and events and the subvenient level. In contrast, he defines an emergent property as one that is not constituted by the parts, properties, events, at the subvenient level, and thus, is a completely unique property. Nonetheless, it is a result of properties at the subvenient level. Moreland then goes on approvingly to quote Andrew Bayley, who claims that the higher level properties, such as hardness and liquidity, that are often claimed to be examples of emergence are merely complex concatenations of so-called bottom level properties.
The problem I see with this formulation is that these higher level properties do not appear constituted by the parts, properties, and events at the subvenient level. In this case, at the atomic level. For example, it seems that one could completely grasp the essential nature of a particular case of the property of liquidity or hardness without even having the concept of an atom. To deny this would be deny that people before the 19th century really understood the essential nature of liquidity or hardness, which seems clearly false.
Thus, the higher level properties do not appear to be merely complex incantations of so-called bottom level properties. Furthers, these properties, or another reason for this, is that these properties could have been produced by an entirely different underlying structure. Even though these higher level properties do not seem different from structural property in Moreland sense, and hand in some sense emergent, they are of no help in understanding consciousness, so I don’t think they help with the issues of the relation of mind to the body.
Now, go with consciousness, then move into mental causation after that. The reason is that, except perhaps for spacial and temporal extension, physical properties that we know of seem to be reducible to their causal powers and liabilities, if you want to speak in those terms. A thing is hard insofar as it behaves in a hard way under appropriate circumstances. Second, the causal powers and liabilities that constitute these higher level properties can, in principle, be completely derived via knowledge of the parts, properties, and events and the subvenient level. Consequently, even if they aren’t ontologically distinct in some way from the complex set of relational and intrinsic properties, the part at the subvenient level, their existence is not puzzling. Consciousness, however, is not reducible to its causal powers and liabilities.
As David Chalmers has stressed, the physical sciences can only explain the physical inabilities in the functions of the systems of the brain, that is, their causal powers and liabilities. The hard problem with consciousness arises because consciousness in qualia cannot be reduced to any set of causal powers or liabilities. Thus, appealing to these, standard examples of emergent properties does not render consciousness in phenomenal qualia less puzzling. Moreland’s paper’s mostly focused on whether mental causation can be understood within a materialist perspective. Non-reductive physicalists often appeal to the notion of top-down causation as somehow helping ameliorate the difficulties reductive physicalism has in understanding mental causation. Thus, Moreland focuses on whether an adequate notion of top-down causation can be found for the case of mental causation.
To see whether the idea of top-down causation helped, we need to get clear on what top-down causation might be in the case of physics, examples of which advocates of top-down causation appeal to, and to do this, we need to look more closely at how causation works within physics. Here, I will generally assume a classical framework of understanding the world, though the points I make apply even more clearly, I think, when one considers the quantum realm. For the sake of explication, I will also assume a substance powers and liability conception of the physical world, though I do not believe this ultimately works for current physics, so I think there’s problems with that view. Consider a surface that reflects red light, but in which individual atoms do not reflect red light.
So, here’s my surface. It’s the use of the bible. Here’s the surface. Red Light. But the individual atoms do not reflect red light, so this is a causal power of the surface itself, the conglomeration of atoms. From a physics perspective combined with the causal powers perspective, the arrangement of the atoms in the surface plus the laws of physics give, so it’s that arrangement plus the laws of physics, give rise to the aggregate of atoms in this surface here, constituting cervix, having the causal power of reflecting red light.
The aggregate of atoms do not directly cause the red light to be reflected but rather, do so indirectly by giving rise to the causal disposition to reflect such light. This causal disposition of the aggregate in turn is what directly causes the red light to be reflected along with the laws of electromagnetism. If we were to place a photomultiplier tube here, above the surface. Here’s my photomultiplier tube. Which upon detecting a red photon coming off, activates a device, here me, that I’ll be the device, that knocks out individual atoms out of the surface, the aggregate of atoms in this surface could then be said to indirectly exert a top-down causal influence on individual atoms in the aggregate here. So, the aggregate itself, through this means of this device, then causes individual parts of it to do such and such.
More generally, when we have an aggregate of parts together in certain spacial temporal relations, physics provides simple rules that allow us to derive the causal power of the aggregate from the intrinsic power of the parts along with the spacial temporal relations between them. Even though the aggregate has a causal power, not in the parts, it is not mysterious in the sense that we can understand how it could be derived via some simple generalizable formula. Further, often to understand the future behavior of members of the aggregate, one must invoke some new causal power of the aggregate, such as reflecting red light, so in this sense, there is top-down causality within physics.
The causal power of the aggregate is necessary to explain the future behavior of the part. For multi-particle aggregates, however, the above causal powers of the aggregates are the only causal powers that there are, so the real problem, I think, is the distinction made between the above time of top-down causality and some purported micro physical causality, a distinction advocates of top-down causality and causality often want to make. So-called micro physical causality, they were talking about, is just the same as this type of top-down causality. There’s not a difference between the two. The question is whether this type of top-down causality is of any help for the issues involving mental causation.
I do not see that it is. One motivation for introducing top-down causation is to attempt to provide room for human agency since purportedly, this allows for something over and above the parts to cause the movement of the body. This, however, covers over the underlying problem. What aggregate to identify the agent with? There’ll be many many aggregates, slightly different causal powers, as we saw with Dean Zimmerman’s talk last night, for example, an aggregate formed by adding or subtracting a neuron. Nothing in physics tells us which aggregate or set of aggregates constitute the experience or actor.
In fact, it seems to identify one of the aggregates with an actor experiencer. One will have to have a special rule that says exactly which aggregates, or which set of aggregates, qualify, and which ones do not. This rule will have to indicate which aggregates are in the set, which are out of the set, and which are neither in nor out, if one allows vagueness. The problem is that there will be a whole continuum of aggregates with an enormous number of seemingly nonconventional ways in which they could differ. And thus, the rule would have to say for all such aggregates, which ones are in and which ones are out.
In the case of the human experience or an agent, however, there does not seem to be any plausible simple rule to determine this. Hence, we are stuck with adding a new, enormously complex law, I would claim. Introducing the idea of a form of top-down causation that involves causal overdetermination also does not help with another aspect of the problem, the importance that meanings and reasons play in our mental lives and physical, or this form does not help with this other problem, the importance that meanings and reasons play in our mental lives and physical behavior.
Consider the difference in response of someone to the statement “your son went to bed” versus the statement “your son is dead.” This would normally cause a great difference in behavior, even though the sound hitting the ear is similar. This difference in behavior can be easily explained in terms of what is meant to the person and how meanings are connected with context. In everyday life, this form of explanation is highly predictably successful, allowing us to make all kinds of novel predictions concerning people’s behavior. In fact, the number of novel predictions is far more than any assigned scientific theory since there are an unbounded number of new sentences that can be constructed and new context in which they can occur.
Yet, we can easily determine what linguistic and other types of responses are appropriate and those are not with the prediction, in this case, being that normal people, for normal people, appropriate responses are much more likely to occur than inappropriate responses. Call this the Everyday Theory of Mind and Meaning. The problem for the materialist, whether physicalist versions or more general supervenience theories, is making sense of the predictive power of this everyday theory. A lemonade materialism does not even attempt to make sense of its predictive power. This is a completely unscientific attitude.
In the history of science, new theories must make sense of the predictive power of older theories. Einstein’s theory of gravity would be unacceptable if it did not make sense of the predictive successes of Newton’s theory of gravity. The materialist theory that comes closest to trying to make sense of it is functionalism. Though Moreland states he will not be addressing functionalism, I think seeing how functionalism would address the issue is helpful. A functionalist account of meaning would claim that the meaning of a concept is given by its dispositional connection to other concepts, some of which have dispositional connections to the surrounding environment. This is similar to structuralism interpretations of mathematics, where the meaning of a number is given by how it interrelates with other terms in an asymiotic system. This view of meaning opens up the possibility of brain states corresponding to concepts.
If we could understand meaning and content in that way, then, for example, statements about one mental state causing another could be spelled out in terms of causal dispositions corresponding to the content of the first mental state causing another physical state with causal dispositions corresponding to the second mental state. A similar account could be given for a mental state causing a physical state. Moreover, such an explanation does not involve any causal overdetermination, and thus, is not in conflict with the micro physical explanation. A micro physical explanation would say that the causal dispositions corresponding to the first and second mental states were the result of the respective micro physical configurations.
This causal story be told is that the aggregate corresponding to the first micro physical configuration has a certain set, like my body, has a certain set of causal dispositions as a result of the laws of physics. The first mental state refers to the subset of those, these causal dispositions that has the relevant causal dispositions and relations. The member of this subset then cause another micro physical state, which in turn, realizes another set of causal dispositions. Subset of this latter set corresponds to the second mental state.
Hence, the first mental state causes the second mental state without there being any causal overdetermination. What is the mistake being made by those who think causal overdetermination is needed? In this kind of case, although I’m not familiar, not very familiar with the relevant literatures, my area, my guess is that they think that one micro physical arrangement causes another micro physical arrangement.
Then, the causal dispositions correspond to the respective functional states are thought of as supervening on the corresponding micro physics and being causally efficacious, and hence, we have two causes, that of the mico physical state and that of the relevant subset of dispositions supervening on them. The mistake is to think that one micro physical arrangement directly causes a second micro physical relation, arrangement. Rather, the laws of physics dictate that the aggregate in the particular arrangement has a set of causal powers and it’s those causal positions that are the direct causes.
So, there is no causal overdetermination. Under functionalism, therefore, the difference between a functionalistic count and a micro physical count of a particular case of mental causation is that the former only invokes the relevant causbel disposition, whereas the latter also provides the micro physical state that realizes those dispositions. The direct causes to which they refer are the same. So, I still allow micro physical arrangements to cause other micro physical arrangements, if you want to talk that way, but they do it indirectly by giving rise to these causal dispositions, which in turn, then cause the other micro physical relationship.
At least for functionalism, my conclusion is the real problem lies elsewhere, namely in not being able to account for qualia, not providing an adequate account of content, and not providing an adequate account of the unity of consciousness. If one rejects functionalism, does adding new powers over and above those in physics help? If such causal powers and dispositions are to be compatible with causal closure, then the subset of those powers then involve interacting with the physical world will have to be isomorphic to the causal powers and dispositions invoked by functionalism.
Hence, if functionalism cannot account for meaning and content, neither will this subset of causal powers. A non-functionalist who appeals to top-down causality, therefore, owes us an account of how additional causal powers beyond this subset helps, and how they in turn connect with the ones that affect the physical world. Further, since I think the form that from the perspective of current physics, a causal power is physical if it is describable mathematically, the way these additional causal powers interact should be mathematically describable, otherwise your solution amounts to no more than providing another layer of physical reality that current physics has to discover.
The same problems for standard physicalism would then arise for that layer. If it is not mathematically describable, then arguably, it runs into the same problems as they claim dualism runs into. In any case, this kind of analysis, this is the kind of analysis that needs to be carried out instead of appealing to some sort of top-down causality as a magic wand that will overcome the problems facing physicalism. And just say that was where the end of this leads. I think that the core problem I’m getting at here is the idea that the structural arrangements directly cause anything. There is this micro physical causality instead of its being the causal disposition that the laws of physics give to that structural arrangement that are the primary direct causes. Okay, that’s it. [applause]