The Format of Thought: a Dynamical Systems Approach to Intentional Action Susan Schneider Department of Philosophy, Center for Cognitive Neuroscience, and Institute for Cognitive Science University of Pennsylvania Aim • DST purports to be a theory of the nature of thought. • View of DST in mainstream philosophy of mind: Unclear on how low-level explanations in DST can inform traditional philosophical problems such as the mind-body problem, mental causation, the nature of mental states/events, and the free will-determinism debate. • Today: quick discussion of novel DST view of mental causation. Use this view of mental causation to develop a position on the free will debate for DST (“Neurocompatibilism).” Approaches to the Nature of Thought • Naturalism: explain how mental phenomena fit into the world that scientific investigates. • Naturalistic approaches to conceptual thought: • Connectionism: conceptual thought is a species of pattern recognition in which activation patterns spread though a connectionist network (Paul and Patricia Churchland, Paul Smolensky). • Symbol processing approach. Conceptual thought is the manipulation of symbols according to algorithms (Fodor, Pinker). • DST – cognitive systems are kinds of dynamic systems, and as such, they are best understood from the perspective of DST. DST Approach to Mental Causation • Normal model of causation is “linear causation” (“efficient causation”, “billiard ball causation”) in which event E1 brings about E2. DST: different approach. • Freeman: “Linear causality fails most dramatically in studies of the relations between microscopic neurons and the mesoscopic populations in which they are embedded...Such interactions are not particular to neurons in neuropil, being common in familiar systems such as hurricanes, lasers, fires, herds…In each of these cases, particles making up the ensemble simultaneuously create a mesoscopic state and are constrained by the very state they have created.” (p. 129) DST and Mental Causation, cont., • Scott Kelso, “In synergetics, the order parameter is created by the cooperation of the individual parts of the system, here the fluid molecules. Conversely, it governs or constrains the behavior of the individual parts. This is a strange kind of circular causality (which is the chicken and which is the egg?), but we will see that it is typical of all self-organizing systems. What we have here is one of the main conceptual differences between the circularly causal underpinnings of pattern formation in nonequilibrium systems and the linear causality that underlies most of modern physiology and psychology…” (Kelso, 9) • “Circular Causation”: higher-level emergent patterns generate downward causal influence on the physical level. • Philosophers: Is circular causation coherent? Kim’s Exclusion Problem • Not presented against DST specifically, but I’ll apply to case of circular causation. • Idea behind problem: Whenever a mental event is proposed as a cause of another event, whether physical or mental, its status as cause is in danger of being preempted by a physical event—that is, a mental cause is liable to be excluded by a physical cause. • Causal Closure of Physical (i.e., microphysical) Domain. General idea, quoting Kim:, “the physical domain is causally and explanatorily self-sufficient—that is, to explain a physical event, or to identify its cause, there is no need to look outside the physical domain.” • Ex) The biological domain is not causally self-sufficient since nonbiological events (e.g., purely physical events such as exposure to strong radiation, natural disasters) can cause biological changes. Exclusion Problem, cont., • Now consider circular causation. Suppose that a mental event M, occurring at t, causes a physical event P. From the Causal Closure Principle, it follows that there is a physical event, P*, occurring at t, which is a sufficient cause of P. • Kim. This already is an “uncomfortable picture”: Whenever a mental event has a physical effect, the physical effect has a purely physical cause as well. So there is causal overdetermination (and making the supposed mental cause dispensable). And consider: • Causal Exclusion. No event has more than one sufficient cause occurring at t—unless it is a genuine case of causal overdetermination. • “Unless one opts for the strange view that every case of mental causation is a case of causal overdetermination, the exclusion principle must be applied to the present case. Since each of M and P* is claimed to be a sufficient cause of P, either M or P* must be excluded as a cause of P. But which one?” • Kim: M must go. “The reason is simple: if we let P go, the Causal Closure Principle kicks in again, requiring us to posit a physical sufficient cause, say P**, for P. (What could P** be if not P*?) And we are off to an unending regress….” DST Response to Kim • DST has two options: (1) Drop causal closure principle. (2) Drop notion of circular causation, accepting linear causation instead. Saying that higher-level states are realized by complexes of physical states, and the physical states really do the casual work. (Important: consistent with explanatory import of higher-order vocabulary). • DST wants first option, but which is one correct? Depends on your metaphysical views about the nature of properties. Debate Over Property Natures (in Metaphysics) • Are property natures a matter of their purely “intrinsic” or internal natures, or their causal powers/dispositions? (Lewis vs. Shoemaker). • Categoricalism/Categorialism: property natures are not determined by any causal powers, they are “internal” to the property itself (Armstrong, Lewis). • Ask: how are fundamental particles taxonomized? By what they do. • Can property natures really be separated from their causal powers? (What would it be like to say that F is a mass property but F does not do what it does in our world). • Dispositionalism: property natures are determined by causal powers/dispositions of properties (Schoemaker). “Dispositionalist” Option • Suppose property natures are determined by their causal powers. Then, microphysical property dispositions could determine the causal powers of complexes of particles that realize macroscopic brain events that seem to be exhibiting “circular causation”. • In such a case, the causal closure principle is TRUE. Physical properties, because they are complexes of causal powers, determine the causal powers of the order parameter. (The causal power of the order parameter is a higher level property that is metaphysically comprised of the lower level properties). Categoricalism: Causal Closure is False (DST Option) • Now let’s look at other option. The causal powers of a property are irrelevant to property natures. • In this case, it is difficult to see how (micro)physics is causally closed. The laws of microphysics, together with the pattern of microphysical properties in a brain, wouldn’t determine the brain’s higher-level patterns (e.g., that there is a certain order parameter). • I’m going to take this option. DST thinks it has irreducibly higher-level causation. I’ll now apply this novel form of causation to the problem of free will. The Problem of Free Will • Humans are unique creatures, at least relative to other creatures on Earth, as we are at a high enough stage of intellectual development to reflect on whether our actions are truly free. • We recognize a conflict between two perspectives we have on ourselves. We see ourselves as free agents; yet we also see our behavior as being determined by underlying causes that we at least sometimes are not fully aware of. • Problem of Free Will: Are my intentional actions genuinely free, or are they determined by laws of nature, together with antecedent states of my brain? Why Does the Problem of Free Will Matter? • Free will is associated with a cluster of related themes: • Genuine creativity • Self-control • Self-dignity • A sense of desert: we deserve what we get • Autonomy • Moral responsibility • And related to this, free will is associated with various attitudes that we have toward our own and other‟s behavior: gratitude, vengefulness, resentment, admiration, desire to see them/ourselves punished. The Deterministic Perspective • On the other hand, we also view ourselves from various impersonal, scientific, or objective perspectives. For instance: • Our ability to think depends upon the well-being of our brains. Aren‟t our decisions to act in a certain way determined by the underlying forces at work in our brains? • A simplified view (not the DST picture): At any time t, the configuration of particles in your brain is determined by where the particles were located (at t-1), together with the laws of physics. Determinism Defined • Determinism: Any event is determined just in case there are conditions (e.g., acts of God, the laws of nature, social pressure, states in the brain) whose joint occurrence is sufficient for the occurrence of the event: it must be the case that if these conditions jointly obtain, the determined event occurs. Quantum Mechanics • How can • Visualization of determinism even wave function of aspire to being true hydrogen atom given that quantum mechanics says the fundamental nature of the world is indeterministic? Quantum Mechanics and Determinism • Det: given that event e occurs, event f must occur. • If QM is true, strictly speaking, determinism is false at the quantum level. • Where does this leave the free will debate? • Philosophers: not much of a change. The chance of a given particle decaying in say, 2 hours, is still “determined” by the laws of QM. That is, events are probabilistically constrained, or guided by, antecedent conditions, together with the laws. What Position should DST take on Free Will? • Suspicion? Would renouncing linear causation as model of mental causation dissolve the problem of free will? • The problem of free will arises with circular causation too: – Suppose M is a mental event and that further, we act in virtue of M, picking up a coffee cup. Further suppose that (as per circular causation) M brings about physical event P1 by downward causation. P1 then causes the picking up of the cup. – The free will problem emerges: Is the happening of M determined by the laws of nature, together with antecedent events? Or does M somehow “break free” of the laws? The Sense in Which We Think We Have “Free Will” • To answer the question of whether we act freely for DST, we must ask: What is genuine free will to begin with? Standard view: • From a subjective standpoint, we perceive ourselves as free agents who are able to influence the world in numerous ways. In many cases, we see before ourselves a field of possible actions, out of which, we freely choose one. • There‟s a sort of “up to us-ness” associated with our actions: our actions are under our control. For any action A, we might have done otherwise. • S has free will when: (a), it is “up to us” what we choose from a field of possibilities (b), the origin of our choices and actions is in us and not in anyone/anything else over which we have no control. DST and Free Will • Suppose DST can give a plausible account of intentional action (e.g., Freeman, Ch. 5, 2000). • At first blush, this doesn’t limit DST to a certain position on the free will debate. • An account of intentional action doesn’t require that the actions be “genuinely free”; they could be determined. Indeed, DST explains action in terms of the evolution of a dynamic system – this sounds sympathetic to a kind of determinism. • On the other hand, most of us think that there is a sense in which some actions are free and others are not: e.g., Joe doesn’t act freely when a gun is pointing at him, but he does when he picks a vacation spot. A neurobiological theory of intentional action should explain such differences, giving a sense in which certain actions are free. Taxonomy of the Positions on the Debate over Free Will • There are two primary ways one can be a proponent of Free Will or Determinism: • 1. One can be a Compatibilist: Free Will and Determinism are compatible with each other. • 2. One the other hand, one can be an Incompatibilist. In this case, either (a), you believe in free will and you don‟t believe in Determinism (“Libertarian”); or (b), you believe in determinism and reject free will (“Hard Determinism”). • Argue: DST is incompatible with Libertarianism. Develop a novel Compatibilist position for DST: “Neurocompatibilism.” • (We could also develop a Hard Determinist view). INCOMPATIBILISM (Libertarian/Free Will Version) • “Libertarians”: free will is incompatible with determinism. Further, free will exists (thus, determinism is false). • Libertarians often urge that free intentional action involves a form of causation that is unique to mental causation, and not normal event causation (i.e., linear causation). Perhaps circular causation is such? Randomness Problem for Libertarianism • A major task the Libertarian faces is showing that there is a real sense in which there is free will that is not compatible with determinism. • What is it for an event to be an act of free will but not determined? Would it be random? Truly random events aren’t under the control of anyone or anything. How would that be free will worth having? No one would be responsible for their actions. Libertarian Reaction • There are a few ways that the Libertarian reacts to the worry that if events aren‟t determined, they are merely random, not giving us true freedom or moral responsibility. One is of interest: • There is a new form of causation by an agent that is not normal event causation. This was developed by Rodrick Chisholm, who contrasted normal event causation with „agent causation‟ (a special form of causation minds employed). • Big Issue for these theories: We have a physical world of physical causes, on the one hand, and a distinct realm, of agent causes, on the other. But how do agents causally interact with the physical world of event causation? How do our freely willed thoughts enter into the world of physical causes and effects? (Like interaction problem with Cartesian Dualism). • DST can answer this in a naturalistic way. Introduce circular causation as a novel form of causation associated with intentional action. It is not a mystery how emergent features effect the microphysical realm. Avoids problems with Chisholm‟s account. Neurocompatibilism – Is DST really compatible with a Libertarian position? If causal closure was violated by mental features there is a sense in which one breaks free of physical laws. If “Determinism” means “determined by physical laws,” then the view is genuinely Libertarian. But if determinism means “determined by laws” (including special science laws) then the view is Compatibilist. This is a more common way of formulating Determinism, and was how I formulated it . – So: Let‟s see what a Compatibilist DST view looks like. (Compatibilism: FW and Det. are compatible). Problems for Neurocompatibilism 1. Emergent phenomena in general can exhibit downward causation, but, intuitively, only minds exhibit free will. So, exhibiting downward causation is a necessary condition for a system acting on the basis of free will, but it is not a sufficient condition. Problems, cont., 2. Content of beliefs, desires, etc. are both reasons for the action and causes of the action – Davidson, Fodor. What are the correlates of concepts according to DST? Need these for a DST theory of FW as Compatibilism is supposed to accommodate our ordinary framework of attribution of blame, praise, etc. 3. Recent Revolution in Free Will Debate: the work of Benjamin Libet • - Bigger Problem: • Now, humans only become Neurocompatibilism will aware of the intention to need to deal with Benjamin act 350-400 msec. after RP Libet‟s work on free will. starts, but still before the motor act. • Libet. Freely voluntary acts are preceded by a specific electrical change in the brain (the “readiness potential”, RP) that begins 550 msec. before the act. (This is almost the same amount of time it takes to utter two syllables). Libet Revolution, cont. • As Bill Banks and Sue Pocket explain: “The issue is this. Libet‟s clear-cut finding was that his subjects consciously and freely „decided‟ to initiate an action only after the neurological preparation to act was well under way. This implies that the conscious decision was not the cause of the action.” Banks/Pockett on Libet, cont., • „If conscious decisions are not the cause of actions, it follows that we do not have conscious free will. Even worse, because the ability consciously to initiate actions is an essential property of self, the denial of conscious, personal origination of action is a challenge to our sense of selfhood. The implication is that we, our conscious selves, are not free actors with control over our choices in life. We are only conduits for unconsciously made decisions. Libet‟s one simple experiment has slipped our entire self-concept from its moorings.” Is Compatibilism Dead? • At first blush at least, this is a clear attack on free will, (both the Libertarian and Compatibilist versions). Seems to support Hard Determinism. • The “volitional” process is initiated unconsciously! • We seem to closely associate consciousness with free will, so it seems like this isn‟t a case of free will. Carving out a Free Will position? • Libet is saying that consciousness could still control the outcome; it can veto the act. So do we have a more limited sort of free will? Libet Revolution, cont., • Some say it is only “free wont”. On the other hand, if you can veto something, there‟s a sense in which for the relevant action that you did not veto, you „could have done otherwise‟ (you could have vetoed it). • For many, free wont will not be sufficient for free will. • Try to do a bit more for Compatibilism. Nonconsciously initiated actions can be free. Libet, cont., Ex) Tennis match with Venus Williams. - Did you consciously intend to return her serve before action initiation? No way. - As you learned to play tennis, you consciously intended to master actions that, due to all your practice, you now initiate involuntarily and non-consciously. So, in a sense, the actions are initiated freely. To go back to our def. of FW, “the origin of the choice is in you.” It is not as though, contra your purpose in the game, you mysteriously initiated a “return the serve” move when you were at the net. Your returning the serve is very much a part of you. - Although the paradigm cases of free will are conscious ones (ones in the global workspace before initiation of motor action); non-consciously initiated actions can be acts of free will (in a derivative sense) as we freely chose to develop these skills. - They just aren‟t the paradigm cases. - Conclusion: Libet‟s results are not contrary to Neurocompatibilism. Conclusion • Looked at the novel view that DST has of mental causation. • Applied it to FW, noting relation to issue about property natures. • Suggested a possible view on FW debate and replied to the Libet issue.
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