Derek Bolton and Jonathan Hill have embarked on an ambitious project with the purpose of arguing for the necessity of retaining both psychological and psychiatric sorts of explanations for mental disorder. This includes arguing for two distinct kinds of causation. These two kinds of causation are sometimes both required in order to explain mental disorder. In the following review I first attempt to sketch their overall project. Then I offer a criticism of their view that two notions of causality are needed in order to properly explain mental disorder.
2. In order to explain the different ways that an intentional system can malfunction, the authors make use of Daniel Dennett's (1987) distinction between adopting a physical stance and adopting a design stance toward a system. A system can go wrong (i.e., not achieve its purpose) either because it is poorly designed or because its physical components that implement the design break down. One of the authors' primary goals is to argue that sometimes it is appropriate to implicate neurophysiology (i.e., using the physical stance) in disorder and sometimes it is appropriate to implicate the subject's intentional system in disorder (i.e., using the design stance). Sometimes both kinds of causality are needed in order to explain disorder.
3. The burden on the authors is to argue that these two kinds of causality are indeed both necessary in order to explain disorder. For, many hold the view that, ultimately, all mental disorder can be understood in terms of the physics of the brain. Bolton and Hill want to preserve psychology as a discipline that is often necessary for understanding human behavior in terms of the integrity--at a logical and epistemological level of analysis--of people's systems of beliefs, desires, intentions to behave, and other intentional states.
4. In order to argue for their view, Bolton and Hill recognized the need to address certain philosophical questions in the philosophy of mind and meaning. I will focus on the following:
1. Do meaningful mental states have causal power? 2. Are mental states identical to brain states? 3. Are two notions of causality needed in order to understand mental disorder?
5. The authors argue that mental states do have causal power, and they infer this from the fact that attribution of mental states has theory-driven predictive power. The authors hold that individuals' "knowledge and belief in daily life have the form of theories," even if these theories are only implicit. By attributing to individuals a theory that drives their beliefs and actions, we can provide good prediction of their behavior in terms of meaningful mental states. Since one gets good prediction by doing this, then, according to the authors, this warrants the inference that meaningful mental states cause behavior. This conclusion has more force if it can also be shown that meaningful mental states are not identical to brain states.
6. In chapter 2 the authors argue that meaningful mental states are not reducible to brain states. Their argument concludes that "mental states have intentionality while brain states arguably do not."And this means that mental states cannot be identical to brain states. Their argument seems to rely first on the fact that their is nothing obvious in the language of physical brain states that suggests that these states are sensitive to features of the environment. Second, they rely on the fact that the language of intentionality does suggest a sensitivity to features of the environment. The authors acknowledge that the brain plays some role in behavior, viz., by encoding meaning for action. This notion of encoding meaning for action plays the role of bridging the gap between the physics of the brain and meaningful or intentional mental states.
7. The idea seems to be that understanding the physics of the brain allows one to understand only local effects of the brain. At one point the authors refer to an argument by Kincaid (1990) that we cannot reduce intentional causality to non-intentional causality because the same physical entity may serve different purposes and different physical entities can serve the same purpose. Therefore, by looking to the physics of the brain alone, one cannot understand its purpose with respect to normal action in the world. According to the authors, one needs the language of meaning and evolutionary theory for this. Meaning serves the purpose of regulating normal action. And normal action is determine by how evolution has matched our meaningful states to action in the world for survival. Since disorder is apparent in action, and action takes place with respect to the non-local world, according to the authors, the only way to understand disorder is in terms of the breakdown of normal intentionality. Hence, according to the authors, the notion of intentional causality is needed in order to explain disorder.
8. The authors' view on intentional causality is that it has its origin in biological systems which regulate processes in the body for the evolutionary purpose of survival. An example that the authors use is the regulation of the cardiovascular system. The "patterning of the impulses in the regulatory system is directed at or of the blood pressure, and the system has intentionality with respect to blood pressure" . The intentionality of thought is just a more elaborate and more plastic version of this sort of biological case, according to the authors.
9. The notion of intentionality in basic biological systems has explanatory power, according to the authors, because it opens the way for systems to go wrong. As stated above, a system goes wrong when its design is poor or when the implementation of the design breaks down. When implementation breaks down, then the disorder is at least partially a psychiatric one, as opposed to a psychological one. Psychiatric disorder is the kind of disorder that requires explanation by appeal to non-intentional causality.
10. Psychological disorder, on the other hand, is made possible because of the plasticity involved in learning. This notion of plasticity in higher level intentional systems opens the way for poor design. Since it is possible for subjects to learn many different sets of rules for behavior, it is possible for the subject to learn inappropriate sets of such rules; and this, Bolton and Hill argue, can lead to psychological disorder of the kind that requires explanation by appeal to the notion of intentional causality. According to the authors, there are two ways that psychological disorder might arise. Either the subject's intentional states persistently fail to represent the world correctly, or the rules for behavior learned by the subject during life persistently enter into conflict.
11. I am sympathetic to this sort of view, but I have some concerns. Although the authors may have shown that it is possible to understand disorder in psychiatry and psychology in terms of two different notions of causality, I don't think that they have shown that it is necessary to do so. According to their view, disorder occurs when there is a misfit between meaningful states and the subject's action in the environment, where a misfit is determined by what sort of fit evolution has provided us with. Moreover, they hold 1) that meaningful states cannot be merely physical states because mere physical states don't seem to be capable of intentionality (a notion of encoding is necessary); 2) that one cannot understand disorder by considering only the physical states of the brain because physical states don't tell us enough about what the subject ought to be doing in his/her environment; 3) only a functional perspective will do when it comes to disorder, where we have a baseline in evolutionary theory for what counts as a normal fit between the subject and the environment; and 4) that materialism is true. It seems to me that (1) and (2) are wrong and (3) and (4) are arguably right.
12. The authors hold (1) because they cannot conceive of how physical states have intentionality, except through encoding. It may be correct that physical states cannot, alone, possess intentionality. However, as we learned from Arnauld's sort of criticism of Descartes' arguments for mind-body dualism, just because one cannot conceive of physical states having mental properties does not mean that they don't.
13. The authors hold (2) because the same physical entity could serve different purposes and a different physical entity could serve the same purpose. So, by looking at just brain states, the argument goes, one could not figure out their purpose. However, it seems to me that this is irrelevant if (3) is true. If what counts as disorder is a bad fit between the subject and the environment, then one could make the case that one ought to be doing evolutionary psychiatry. In other words, one can seek to determine what counts as an abnormal fit between the brain (its states, processes, etc.) and the environment. Just as the authors point out, what matters in disorder is the fit between the subject and the environment. If fit is what we need to determine, then psychiatry could explain disorder in term of how the brain fits its environment. This would not involve consideration of just the brain, but also of the subject's fit to his environmental niche (Clune, 1999).
14. Moreover, the authors, I take it, hold that functional patterns of neurons firing are what encode meaning, for they are materialists (4) who reject the identity of brain states and meaning. And such patterns of neurons firing are likely to meet the authors' definition of intentional causation. Such patterns of neurons firing certainly have an evolutionary function like the patterns of pulses that regulate blood pressure. Therefore, again, why not work on explaining how patterns of neurons firing are supposed to fit (behavior and) the environment, and forget about intentionality altogether? Disorder can be understood as a persistent misfitting between patterns of neurons firing and the proper functioning of the subject in the environment.
15. For the above reason, I think the authors are not right in insisting that disorder cannot be explained solely at the physical level. Perhaps the knowledge and technology has not yet arrived at the point where evolutionary psychiatry can flourish, but it is possible for it to flourish in the future. For now, perhaps, the authors' method is a viable one. To borrow from Daniel Dennett, just as the notion of gene was helpful to biologists before we knew much about it's actual structure, perhaps the notion of explaining disorder in terms of a "(serious) failure of meaningful connections between mental states and reality, or among mental states, or between mental states and action" might be helpful for the time being to explain disorder, but eventually can be discarded altogether.
. Bolton and Hill, chapter 8.
. Bolton and Hill, p. 39.
. Bolton and Hill, p. 116.
. Bolton and Hill, pp. 79-80
. Bolton and Hill, section 2.4.2
. Bolton and Hill, p. 230.
. Bolton and Hill, pp. 191-199.
. Bolton and Hill, p. 222.
. Bolton and Hill, pp. 240, 252-263
Bolton and Hill. (1998) Mind, Meaning and Mental Disorder (Oxford, New York, Tokyo: Oxford University Press, p. xvi.).
Bolton, D. & Hill, J. (2001). Precis of "Mind, Meaning & Mental Disorder: The Nature of Causal Explanation in Psychology & Psychiatry" Psycoloquy 12(018) http://www.cogsci.soton.ac.uk/psyc-bin/newpsy?12.018
Clune, Alan C. (1999). "Saving Behaviorism Through Evolutionary Theory," in the proceedings (CD-ROM) of the 14th Annual Interamerican Congress of Philosophy held at The Autonomous University of Puebla, Puebla, Mexico, August 16-20. Here I propose using the evolutionary niche in order to understand normal behavior. Also see Barry Smith, "The Niche," in Nous, vol. XXXIII, no. 2, June 1999.
Dennett, Daniel. (1987). The Intentional Stance (MIT Press: Cambridge, MA).
Kincaid, H. (1990). "Molecular Biology and the Unity of Science," Philosophy of Science, 57, 575-93.