Henry Stapp is a quantum physicist who worked with both Wolfgang Pauli and Werner Heisenberg. In his 2004 book Mind, Matter, and Quantum Theory, he develops a psychophysical theory of mind that depends on our modern understanding of reality in the light of quantum mechanics. Stapp moves beyond the ideas of a world of classical material particles obeying the laws of Newtonian physics, in which mental events cannot exist. He challenges the mechanical view of man, put in place by René Descartes, strengthened by Isaac Newton's laws of classical mechanics, and then accepted almost universally in the eighteenth and nineteenth centuries. Stapp notes that Descartes left room for freedom in the minds of men. He says
Descartes, in the seventeenth century, divided all nature into two parts, a realm of thoughts and a realm of material things. and proposed that the motions of material things were completely unaffected by thoughts throughout most of the universe. The only excepted regions. where thoughts were allowed to affect matter, were small parts of human brains called pineal glands: without this exception there would be no way for human thoughts to influence human bodies. But outside these glands the motions of all material things were supposed to be governed by mathematical laws.For Descartes, the mind was the locus of freedom and indeterminism (indeterminata). Our bodies, the non-human animals, and the rest of the world, he thought are pure deterministic machines. So one thing that quantum mechanics does is restore indeterminism, breaking the causal chain. For Stapp, this creates alternative possibilities in the mind, one of which can be actualized by a choice that is related to quantum events in the brain. Stapp notes that probabilities in classical physics were considered to be epistemic, the result of human ignorance. The infinite mind of a Laplace demon could comprehend the exact positions and velocities of all the particles of matter, plus the forces acting on them, and thus know the entire past and future of the world, including the thoughts of man. Stapp says quantum mechanics has changed that. Probabilities are now real (ontological), opening the door to mental processes that cannot be understood in terms of material particles.
Stapp's unique quantum mechanical contribution to the free will problem is the claim that the observer's free choice of which experiment to perform, combined with the Quantum Zeno Effect, allows the observer, by his own free choices, to hold stably in place a chosen brain activity that would normally fade away. Stapp describes the observer as asking a question of nature:
It might seem that a mere capacity to pose questions and register answers would leave our mental egos just as helpless and impotent as before. But the quantum mechanical process of posing questions and receiving responses is not like the classical mechanical process, in which our observations have no physical effects. In QM, the observer’s free choice of which question to ask plays a critical role in determining which potential material property will become actualized.Quantum mechanics includes the knowledge of the observer and their knowledge-acquiring actions. And thus an observer's mental intentions can influence physical behavior (as Descartes thought). Following the ideas of In QM, the observer asks Nature a yes/no question about the state of a system...Normally, this dependence of the properties of the system being probed, upon the observer’s choice of question does not give the observer any effective control over the observed system. That is because Nature’s response can be “No”. However, there is an important situation in which, according to the quantum rules, the “No” answers will be strongly suppressed. In that case, the free choices made by the observer can exert effective control over the system being probed – which, in von Neumann’s theory, is the brain of the observer. Suppression of the “No” responses is predicted if an initial “Yes” response is followed by a sufficiently rapid sequence of posings of the same question. In that case the observer becomes empowered, by his own free choices, to hold stably in place a chosen brain activity that normally would quickly fade away. This effect is the celebrated “Quantum Zeno Effect” Werner Heisenberg, John von Neumann, Alfred North Whitehead, Eugene Wigner and others, Stapp develops a theory of human consciousness as a process. Von Neumann and Wigner argued that the collapse of the wave function in any measurement process depends on the actions of a conscious observer. Stapp's ideas are similar in some respects to those of Roger Penrose, the Australian philosopher David Hodgson, and the British philosopher Michael Lockwood. Penrose and Hodgson consider "nonlocal" quantum effects over areas of the brain much larger than the microscopic size of single atomic processes. All these thinkers explore the implications of quantum-mechanical nonlocality that were first made famous by the 1935 Einstein-Podolsky-Rosen thought experiment. Einstein had worried about nonlocality (faster-than-light information about probabilities) in the collapse of a single-particle wave function when he first considered quantum mechanics at the 1927 Solvay conference. Stapp says that in the EPR situation
the combined system of two far-apart particles acts as a single global entity, in the sense that it is not possible to impose the following causality requirement: John Bell had prepared the way with his famous "Bell's theorem". The basic message of Penrose's book, as of mine, is that the enormous changes that have been wrought by quantum theory in our ideas about the fundamental nature of matter have altered radically the problem of the connection of mind to matter."What a scientist decides to do to one part of a system cannot affect in any way how the system will respond at the same instant to a measurement performed upon it far away." Thus a quantum system seems able to behave as a unified entity: What you do to it in one place can influence how it will react to a simultaneous probing far away. The profoundness and irrevocability of this collapse of the classical local-reductionistic conception of the physical universe was not fully recognized even by Einstein, Podolsky, and Rosen: it became clear only after
Stapp explains Bell's theorem and nonlocality
Stapp's Psychophysical Theory of Mind and ConsciousnessStapp's central idea is that the physical world described by the laws of physics is a "structure of tendencies in the world of mind." He builds on Werner Heisenberg's idea of Potentia, and on John von Neumann's two kinds of quantum processes, random and determined. Following Whitehead, he thinks of mind as a creative process. Stapp identifies Mind with the process of creation. Everything that exists is created by this process. In particular, every "reduction" or "collapse" of the wave function adds a bit of information to human knowledge. Stapp's process consists of a well-ordered sequence of creative acts called events. He says that any event is prior to all those that follow it in this sequence, and is subsequent to all those that come before it in this sequence. This sounds like the causal sequence of classical determinism. Following Whitehead's book Process and Reality, he describes each creative act as a grasping, or prehension, of all that has been created by prior acts in a novel but unified way. Stapp endorses novelty and creativity. He says, "Each creative act brings into existence something fundamentally new: it creates a novel "emergent" quality."
Stapp says a wave function collapse can increase human knowledge.
A wave function that represents the brain is all smeared out. All these quantum mechanical possibilities are there on an equal footing. If I'm going to say something, for example, there are a lot of possibilities for what I might say. The way quantum mechanics works there is this mysterious thing called the collapse (or reduction) of the wave function. What happens is, this big smear of possibilities - or potentialities - suddenly get reduced. This reduction is associated with an increase of knowledge.Stapp is right. In Claude Shannon's theory of information, if multiple possible messages exist, when one is received there is an increase of information (knowledge). But Stapp does not want the next thing he says to be a matter of chance. So we must limit ontological quantum-mechanical randomness in the brain to generating those alternative possibilities for what Stapp wants to say, and leave his "true choice" of what to say to an adequately determined evaluation and selection process. This is the two-stage model of free will. Stapp is clear that his "true choice" cannot be left to chance.
Stapp on ChanceStapp says that he is uncomfortable with the idea that there is in nature, at its most basic level, an irreducible element of chance. He finds it unthinkable that between two possibilities there can be a choice having no basis whatsoever. "Chance is an idea useful for dealing with a world partly unknown to us. But it has no rational place among the ultimate constituents of nature," he says. See William James on this "antipathy to chance." On the relationship between chance, necessity, and free will, Stapp says,
Man's free will is no illusion. It constitutes his essence. And it rests upon the law of necessity. Any play of chance would falsify the idea that I, from the ground of my essential nature, make a true choice.This sounds like the oft-cited claim that "free will requires determinism, and is inconceivable without it." But only an adequate determinism is required for a determination by the will. See R. E. Hobart and Philippa Foot. Moreover, the claim that chance has no rational place is extreme. It is part of the standard argument against free will. We must limit chance to providing the alternative possibilities for Stapp's "true choice" to choose from.
The Brain a ComputerStapp thinks the brain is a computer that reprograms itself, as do many cognitive scientists (e.g., Daniel Dennett).
The brain is viewed in this theory as a self-programming computer, with the aforementioned mutually exclusive self-sustaining neural patterns acting as the carriers of the top-level codes. Each such code exercises top-level control over lower-level processing centers, which control in turn the bodily functions, and, moreover, construct the new top-level code. This new code is constructed by brain processes acting in accordance with the causal quantum-theoretic laws on localized personal data: the new code is formed by integrating, in accordance with directives from the current top-level code, the information coming from external stimuli with blocks of coding taken from codes previously stored in memory. This causal process of construction necessarily produces, by virtue of the character of the quantum-theoretic laws, not just one single new code, but a superposition of many, each with its own quantum-mechanical weight. The conscious act has as its image in the physical world, as represented by contemporary physical theory, the selection of one of these superposed codes. The selection will be determined almost completely by the causal quantum-theoretic laws acting on the localized personal data, provided only one of the superposed codes has non-negligible weight. But if several of these codes have appreciable weight, then the global and seemingly statistical element will become important. Thus the selection process has, from the quantum-theoretic viewpoint, both a causal-personal aspect and also a stochastic-nonpersonal aspect. This model of the connection between mind and matter is in general accord with the ideas of Sperry and Eccles, but is more specific. The conscious act is represented physically by the selection of a new top-level code, which then automatically exercises top-level control over the flow of neural excitations in the brain through the action of the quantum-theoretic laws of nature. The unity of conscious thought comes from the unifying integrative character of the conscious creative act, which selects a single code from among the multitude generated by the causal development prescribed by quantum theory.Some of Stapp's thoughts about information resonate with those of information philosophy.
The basic theme of both Copenhagen and post-Copenhagen quantum theory is that the physical world must be understood in terms of information: the "tiny bits of matter" that classical physics had assumed the world to be built out of are replaced by spread-out nonmaterial structures that combine to form a new kind of physical reality. It consists of an objective carrier of a growing collection of "nonlocalized bits of information" that are dynamically related to experiential-type realities.Each subjective experience injects one bit of information into this objective store of information, which then specifies, via known mathematical laws, the relative probabilities for various possible future subjective experiences to occur. The physical world thus becomes an evolving structure of information, and of propensities for experiences to occur, rather than a mechanically evolving mindless material structure. The new conception essentially fulfills the age-old philosophical idea that nature should be made out of a kind of stuff that combines in an integrated and natural way certain mind-like and matter-like qualities, without being reduced either to classically conceived mind or classically conceived matter. This new quantum structure entails the validity of all the scientifically validated empirical data, while at the same time explaining how our thoughts can influence our actions in a way concordant with our normal experience of that connection. deterministic unitary time evolution of the "wave-function" of a quantum system described by the Schrödinger equation of motion, valid when the quantum system can be treated as isolated, so interactions with other systems can be ignored. The second process is the discontinuous and indeterministic instantaneous "collapse" of the system wave function from a superposition of various possible states into a single state of the quantum system and an interacting system (generally a measurement apparatus). John von Neumann called the collapse of the wave function Process 1. He called the unitary time evolution Process 2. These are not easy to remember. Stapp has suggested calling the first process the Schrödinger process and the second the Dirac process. It was Dirac who showed how the wave function could be transformed from its original representation before any interaction into a new linear combination (or superposition) of new wave functions that better represent the state of the original system interacting with a measuring apparatus. Then upon interaction, the continuous and deterministic unitary evolution ceases when the system collapses indeterministically and discontinuously (Dirac's projection postulate) into one of the eigenstates of the combined system plus measuring apparatus. Furthermore, Stapp introduces what he calls the Heisenberg process. This is the "free choice" of the experimenter to decide what experiment to perform - what "question to put to nature" with the experiment. The best experiments yield a single-bit answer to the question, "yes" or no." And they add this single bit of information to the collection of all information - all human knowledge - the objective state of the universe, says Stapp.One might think that the ideas of quantum physics are too counterintuitive for young minds to grasp. Yet students have no trouble comprehending the even more counterintuitive classical idea that the solid chairs upon which they sit are mostly empty space. Children and students who, through their computers, deal all the time with the physical world conceived of as a repository and transmitter of information should grasp far more easily the quantum concept of the physical world as a storehouse and conveyor of information than the classical concept of physical reality as a horde of unseen particles that can somehow be human experience. A thoroughly rational concept into which one's everyday experiences fit neatly should be easier to comprehend than a seventeenth-century concoction that has no place for one's own being as an active agent with efficacious thoughts, a concoction that has consequently confounded philosophers from the day it was invented, and which has now pushed some philosophers to the extremity of trying to convince us that consciousness, as we intuitively understand it, does not exist, or is an illusion, and other philosophers to the point of making truth a purely social construct. In order to free human beings from the false materialist mind-set that still infects the world of rational discourse, a serious effort is needed to move people's understanding of what science says out of the seventeenth century and into the twenty-first. One problem stands in the way of pursuing this updating of the curricula. Most quantum physicists are interested more in applications of quantum theory than in its ontological implications. Hence they often endorse the "Copenhagen" philosophy of renouncing the quest to understand reality, and settling, instead, for practical rules that work. This forsaking by physicists of their traditional goal of trying to understand the physical world means that there is now no official statement as to the nature of reality, or of man's place within it. Still, I believe that there will be near-unanimous agreement among quantum physicists that, to the extent that a rationally coherent conception of physical reality is possible, this reality will be informational in character, not material. For the whole language of the quantum physicist, when he is dealing with the meaning of his symbols, is in terms of information, which an agent may or may not choose to acquire, and in terms of Yes-or-No answers that constitute bits of information. Just getting that one idea across could make a significant inroad into the corruptive materialist outlook that, more than three-quarters of a century after its official demise as a basic truth about nature, still infects so many minds.
Mind-Brain Quantum EvolutionStapp uses these three processes to explain his model of the mind in the "quantum brain."
The evolution of the physical universe involves three related processes. The first is the deterministic evolution of the state of the physical universe. It is controlled by the Schroedinger equation of relativistic quantum field theory. This process is a local dynamical process, with all the causal connections arising solely from interactions between neighboring localized microscopic elements. However, this local process holds only during the intervals between quantum events. Each of these quantum events involves two other processes. The first is a choice of a Yes-No question by the mind-brain system. The second of these two processes is a choice by Nature of an answer, either Yes or No, to that question. This second choice is partially free: it is a random choice, subject to the statistical rules of quantum theory. The first choice is the analog in von Neumann theory of an essential process in Copenhagen quantum theory, namely the free choice made by the experimenter as to which aspect of nature is going to be probe. This choice of which aspect of nature is going to be probed, i.e., of which specific question is going to be put to nature, is an essential element of quantum theory: the quantum statistical rules cannot be applied until, and unless, some specific question is first selected. In Copenhagen quantum theory this choice is made by an experimenter, and this experimenter lies outside the system governed by the quantum rules. This feature of Copenhagen quantum theory is not altered in the transition to von Neumann quantum theory: the choice of which question will be put to nature, is not controlled by any rules that are known or understood within contempory physics. This choice associated a mind-brain-body system is, in this specific sense, a free choice: it is not governed by the physical laws of contemporary physics (i.e., quantum theory). This freedom constitutes a logical “gap” in the dynamical rules of contemporary physical theory. Only Yes-No questions are permitted: all other possibilities can be reduced to these. Thus each answer, Yes or No, injects one “bit” of information into the quantum universe. These bits of information are stored in the evolving objective quantum state of the universe, which is a compendium of these bits of information. But it evolves in accordance with the laws of atomic physics. Thus the quantum state has an ontological character that is in part matter like, since it is expressed in terms of the variables of atomic physics, and it evolves between events under the control of the laws of atomic physics. However, each event injects the information associated with a subjective perception by some observing system into the objective state of the universe.
Von Neumann quantum theory is essentially a theory of the interaction between the evolving objective state of the physical universe and a sequence of mental events, each of which is associated with a localized individual system. The theory specifies the general form of the interaction between subjective knowings associated with individual physical systems and the physical states of those systems. The mathematical structure automatically ensures that when the state of the individual physical system associated with a mental event is brought into alignment with the content of that mental event the entire universe is simultaneously brought into alignment with that mental content. No special arrangement is needed to produce this key result: it is an unavoidable consequence of the quantum entanglements that are built into the mathematical structure. An essential feature of quantum brain dynamics is the strong action of the environment upon the brain. This action creates a powerful tendency for the brain to transform almost instantly into an ensemble of components, each of which is very similar to an entire classically-described brain. I assume that this transformation does indeed occur, and exploit it in two important ways. First, this close connection to classical physics makes the dynamics easy to describe: classical language and imagery can be used to describe in familar terms how the brain behaves. Second, this description in familar classical terms makes it easy to identify the important ways in which the actual behaviour differs from what classical physics would predict. A key micro-property of the human brain pertains to the migration of calcium ions from the micro-channels through which these ions enter the interior of nerve terminals to the sites where they trigger the release the contents of a vesicle of neuro-transmitter. The quantum mechanical rules entail that each release of the contents of a vesicle of neurotransmitter generates a quantum splitting of the brain into different classically describable components, or branches. Evolutionary considerations entail that the brain must keep the brain-body functioning in a coordinated way and, more specifically, must plan and effectuate, in any normally encountered situation, a single coherent course of action that meets the needs of that individual. But due to the quantum splitting mentioned above, the quantum brain will tend to decompose into components that specify alternative possible courses of action. Thus the purely mechanical evolution of the state of the brain in accordance with the Schroedinger equation will normally causes the brain to evolve into a growing ensemble of alternative branches, each of which is essentially an entire classically described brain that specifies a possible plan of action.
Whiteheadian Quantum TheoryStapp said in Foundations of Physics, vol.9, 1979, p.1, that "the model of the world proposed by Whitehead provides a natural framework in which to imbed quantum theory. This model accords with the ontological ideas of Heisenberg, and also with Eintein's view that physical theories should refer nominally to the objective physical situation, rather than to our knowledge of the system." Many years later, he wrote:
There are deep similarities between Whitehead's idea of the process by which nature unfolds and the ideas of quantum theory. Whitehead says that the world is made of 'actual occasions', each of which arises from potentialities created by prior actual occasions. These actual occasions are 'happenings' modelled on experiential events, each of which comes into being and then perishes, only to be replaced by a successor. It is these experience-like 'happenings' that are the basic realities of nature, according to Whitehead, not the persisting physical particles that Newtonian physics took be the basic entities. Similarly, Heisenberg says that what is really happening in a quantum process is the emergence of an 'actual' from potentialities created by prior actualities. In the orthodox Copenhagen interpretation of quantum theory the actual things to which the theory refer are increments in 'our knowledge'. These increments are experiential events. The particles of classical physics lose their fundamental status: they dissolve into diffuse clouds of possibilities. At each stage of the unfolding of nature the complete cloud of possibilities acts like the potentiality for the occurrence of a next increment in knowledge, whose occurrence can radically change the cloud of possibilities/potentialities for the still-later increments in knowledge. The fundamental difference between these ideas about nature and the classical ideas that reigned from the time of Newton until this century concerns the status of the experiential aspects of nature. These are things such as thoughts, ideas, feelings, and sensations. They are distinguished from the physical aspects of nature, which are described in terms of quantities explicitly located in tiny regions of space and time. According to the ideas of classical physics the physical world is made up exclusively of things of this latter type, and the unfolding of the physical world is determined by causal connections involving only these things. Thus experiential-typ e things could be considered to influence the flow of physical events only insofar as they themselves were completely determined by physical things. In other words, experiential-type qualities. insofar as they could affect the flow of physical events, could - within the framework of classical physics - not be free: they must be completely determined by the physical aspects of nature that are, by themselves, sufficient to determine the flow of physical events. The core idea of Whitehead's thought is, I believe, that the experiential aspects are primary: they control the physical, rather than the other way around. It is therefore interesting to inquire about the direction of the flow of causal influences in the quantum picture of nature: Are the experiential qualities still slave to the physical quantities? This question of which way the causal influences runs is probably the most basic question in both science and philosophy: Are the physical aspects of nature in complete charge, as they are in the classical picture of nature, or do the experiential aspects of nature have a degree of autonomy that can feed into, and effect in significant ways, the flow of physical events? The issue here is whether the physical description is self-sufficient? Are the experiential aspects of nature merely consequences of the physical aspects, whose dynamical evolution is completely specified by laws of nature that involve only these physical aspects themselves - together with random elements that represent aspects of nature that are beyond the scope of human experience - or do experiential-type things, uncontrolled by the physical aspects, enter in an essential way into the dynamical connections that guide the evolution of physical aspects.I shall argue here that the structure of quantum theory renders the physical description non self-sufficient. The experiential aspects of nature enter into the dynamical rules that determine the unfolding of physical reality by way of needed choices that are specified neither by the deterministic aspects of quantum laws, nor by the random elements that enter into quantum theory. Moreover, these 'free' choices can significantly affect the behaviour of an organism that is associated with a sequence of such free choices. This result buttresses Whitehead's idea that subjective elements play a basic role in the process of the unfolding of nature.
Many MindsStapp now explains that the mind-brain can be described as a quantum system that evolves deterministically according to the Schrödinger process, but when the mind puts a question to nature (the Heisenberg process) the answer given by nature is the indeterministic and random stochastic Dirac process. The initial step in the Dirac process is to describe the brain as in a superposition of alternative possibilities for action. Stapp describes this set of alternatives as an ensemble of separate and distinct "classically describable" brain states. He actually imagines the brain "splits" into separate brains which as an ensemble he calls the quantum brain. This greatly resembles Hugh Everett's "splitting" of the universe into separate branches or the famous Schrödinger cat which branches into simultaneous live and dead cats. As early as 1960, Stapp had invented his own "many-minds" theory (and found its fatal flaw, he says).
I have mentioned the Schroedinger evolution of the state S(t) of the universe. The second part of the orthodox quantum dynamics consists of an event that discards from the ensemble of quasi-classical elements mentioned above those elements that are incompatible with the answer that nature returns. This reduction of the prior ensemble of elements, which constitute the quantum mechanical representation of the brain, to the subensemble compatible with the “outcome of the query” is analogous to what happens in classical statistical mechanics when new information about the physical system is obtained. However, in the quantum case one must in principle regard the entire ensemble of classically described brains as real, because interference between the different elements are in principle possible. Each quantum event consists, then of a pair of events, one physical, the other psychical. The physical event reduces the initial ensemble that constitutes the brain prior to the event to the subensemble consisting of those branches that are compatible with the informational content of the associated psychical event. This dynamical connection means that, during an interval of conscious thinking, the brain changes by an alternation between two processes. The first is the generation, by a local deterministic mechanical rule, of an expanding profusion of alternative possible branches, with each branch corresponding to an entire classically describable brain embodying some specific possible course of action. The quantum brain is the entire ensemble of these separate, but equally real, quasi-classical branches. The second process involves an event that has both physical and psychical aspects. The physical aspect, or event, chops off all branches that are incompatible with the associated psychical aspect, or event. For example, if the psychical event is the experiencing of some feature of the physical world, then the associated physical event would be the updating of the brain’s representation of that aspect of the physical world. This updating of the (quantum) brain is achieved by discarding from the ensemble of quasi-classical brain states all those branches in which the brain’s representation of the physical world is incompatible with the information content of the psychical event. This connection is similar to a functionalist account of consciouness. But here it is expressed in terms of a dynamical interaction that is demanded by the requirement that the objective formulation of the theory yield the same predictions about connections between our conscious experiences that the empirically validated Copenhagen quantum theory gives. The interaction is the exact expression of the basic dynamical rule of quantum theory, which is the stipulation that each increment in knowledge is associated with a reduction of the quantum state to one that is compatible with the new knowledge. The quantum brain is an ensemble of quasi-classical components. As just noted, this structure is similar to something that occurs in classical statistical mechanics, namely a “classical statistical ensemble.” But a classical statistical ensemble, though structurally similar to a quantum brain, is fundamentally a different kind of thing. It is a representation of a set of truly distinct possibilities, only one of which is real. A classical statistical ensemble is used when a person does not know which of the conceivable possibilities is real, but can assign a ‘probability’ to each possibility. In contrast, all of the elements of the ensemble that constitute a quantum brain are equally real: no choice has yet been made among them, Consequently, and this is the key point, entire ensemble acts as a whole in the determination of the upcoming mind-brain event. Each thought is associated with the actualization of some macroscopic quasi-stable features of the brain. Thus the reduction event is a macroscopic happening. Moreover, this event involves, dynamically, the entire ensemble of quasi-classical brain states. In the corresponding classical model each element of the ensemble evolves independently, in accordance with a microlocal law of motion that involves just that one branch alone. Thus there are basic dynamical differences between the quantum and classical models, and the consequences of these dynamical differences need to be studied in order to exhibit the quantum effects. The only freedom in the theory — insofar as we leave Nature’s choices alone — is the choice made by the individual about which question it will ask next, and when it will ask it. These are the only inputs of mind to the dynamics of the brain. This severe restriction on the role of mind is what gives the theory its predictive power. Without this restriction mind could be free to do anything, and the theory would have no consequences. Asking a question about something is closely connected to focussing one’s attention on it. Attending to something is the act of directing one’s mental power to some task. This task might be to update one’s representation of some feature of the surrounding world, or to plan or execute some other sort of mental or physical action. The key question is then: Can this freedom merely to choose which question is asked, and when it is asked, lead to any statistical influence of mind on the behaviour of the brain, where a ‘statistical’ influence is an influence on values obtained by averaging over the properly weighted possibilities. The answer is Yes!
Stapp on Free WillStapp argues for an agent-generated choice that is a causal gap that leads to a causal psychophysical link in a quantum mechanically described brain.
The principled quantum uncertainties entering at the microscopic levels of brain processing cannot be confined to the micro level, but percolate up to the macroscopic regime. To cope with the conflict between the resulting macroscopic indefiniteness and the definiteness of our conscious experiences, orthodox quantum mechanics introduces the idea of agent-generated probing actions, each of which specifies a definite set of alternative possible empirically/experientially distinguishable outcomes. Quantum theory then introduces the mathematical concept of randomness to describe the probabilities of the various alternative possible outcomes of the chosen probing action. But the agent-generated choice of which probing action to perform is not governed by any known law or rule, statistical or otherwise. This causal gap provides a logical opening, and indeed a logical need, for the entry into the dynamical structure of nature of a process that goes beyond the currently understood quantum mechanical statistical generalization of the deterministic laws of classical physics. The well-known quantum Zeno effect can then be exploited to provide a natural process that establishes a causal psychophysical link within the complex structure consisting of a stream of conscious experiences and certain macroscopic classical features of a quantum mechanically described brain. This naturally created causal link effectively allows consciously felt intentions to affect brain activity in a way that tends to produce the intended feedback. This quantum mechanism provides an eminently satisfactory alternative to the classical physics conclusion that the physical present is completely determined by the physical past.
The switch from classical mechanics to quantum mechanics preserves the idea that a physical system has a physically describable state. But the character of that state is changed drastically. Previously the physical state was conceived to have a well defined meaning independently of any “observation”. Now the physically described state has essentially the character of a “potentia” (an “objective tendency”) for the occurrence of each one of a continuum of alternative possible “events”. Each of these alternative possible events has both an experientially described aspect and also a physically described aspect: each possible “event” is a psychophysical happening. The experientially described aspect of an event is an element in a person’s stream of consciousness, and the physically described aspect is a reduction of the set of objective tendencies represented by the prior state of that person’s body-brain to the part of that prior state that is compatible with the increased knowledge supplied by the new element in that person’s stream of consciousness. Thus the changing psychologically described state of that person’s knowledge is correlated to the changing physically described state of the person’s body-brain, and the changing physically described state entails, via the fundamental quantum probability formula, a changing set of weighted possibilities for future psychophysical events. The practical usefulness of quantum theory flows from this lawful connection between a person’s increasing knowledge and the changing physical state of his body-brain. The latter is linked to the surrounding physical world by the dynamical laws of quantum physics. This linkage allows a person to “observe” the world about him by means of the lawful relationship between the events in his stream of conscious experiences and the changing state of his body-brain. It is worth noting that the physically described aspect of the theory has lost its character of being a “substance”, both in the philosophical sense that it is no longer self-sufficient, being intrinsically and dynamically linked to the mental, and also in the colloquial sense of no longer being material. It is stripped of materiality by its character of being merely a collection of potentialities or possibilities for future events. This shift in its basic character renders the physical aspect somewhat idea-like, even though it is conceived to represent objectively real tendencies. The key “utility” property of the theory---namely the property of being useful---makes no sense, of course, unless we have, in some sense, some freedom to choose. An examination of the structure of quantum mechanics reveals that the theory has both a logical place for, and a logical need for, choices that are made in practice by the human actor/observers, but that are not determined by the quantum physical state of the entire world, or by any part of it. Bohr calls this choice “the free choice of experimental arrangement for which the quantum mechanical formalism offers the appropriate latitude.” (Bohr, Atomic Physics and Human Knowledge, Wiley, New York, 1958., p.73). This “free” choice plays a fundamental role in von Neumann’s rigorous formulation of quantum mechanics, and he gives the physical aspect of this probing action the name “process 1” (von Neumann, Mathematical Foundations of Quantum Mechanics. (Princeton University Press, Princeton, NJ, 1955p. 351, 418, 421). This process 1 action is not necessarily determined, even statistically, by the physically described aspects of the theory. The fact that this choice made by the human observer/agent is not necessarily determined by the physical state of the universe means that the principle of the causal closure of the physical domain is not necessarily maintained in contemporary basic physical theory. It means also that Kim’s formulation of mind-body supervenience is not entailed by contemporary physical theory. That formulation asserts that “what happens in our mental life is wholly dependent on, and determined by, what happens with our bodily processes .” (p. 14) Kim indicates that supervenience is a common element of all physicalist theories. But since this supervenience property is not required by basic (i.e., quantum) physics, the easy first step out of the difficulties that have been plaguing physicalists for half a century, and that continue to do so, is simply to recognize that the precepts of classical physics, which are the scientific source of the notions of the causal closure of the physical, and also of this idea of supervenience, do not hold in real brains, whose activities are influenced heavily by quantum processes that require (process 1) physical inputs that are not necessarily wholly determined by what happens with our bodily processes.Stapp cites the work of John Searle who recently accepted the possible involvement of quantum indeterminism in consciousness and free will (John Searle, Freedom & Neurobiology: Reflections on Free Will, Language, and Political Power, Columbia University Press, New York, 2007.). He also looks at the work of Jaegwon Kim (J. Kim, Physicalism, Or Something Near Enough, Princeton University Press, Princeton, NJ, 2005). Both Kim and Searle reject any form of dualism.
Kim [tries] to rule out dualism. But the dualism that he mainly addresses is a stark Cartesian (substance) dualism involving “souls” existing “outside physical space”. He says “My target will be the interactionist dualism of Descartes.” But Quantum mechanics involves a particular kind of dualism: it is a dual-aspect theory. Kim suggests that “dual-aspect” theories are “only variants of property dualism.” He says later that “What has become increasingly evident over the past thirty years is that mental causation poses insuperable difficulties for all forms of mind-body dualism --- for property dualism no less than substance dualism...but I believe that if we have learned anything from the three decades of debate, it is that unless we bring the supposed mental causes fully into the physical world there is no hope of vindicating their status as causes, and that the reality of mental causation requires reduction of mentality to physical processes, or of minds to brains.” (p.156). He gives on the preceding page a supposed way of “generating the problem of mental causation for property dualism” without assuming “the causal closure of the physical”. But his argument includes an assumption “Given that your finger twitching, a physical event, has a full physical cause.” This assumption is indeed less than an assumption of full causal closure of the physical. But in the quantum mechanical explanation of the way that mind causes bodily action the twitching does not have “a fully physical cause.” According to quantum mechanics there needs to be a process 1 action mediating the connection between the psychologically described cause---a pain in this case---and any physical action caused by the pain. But the process 1 action has no known or necessary fully physical cause. A quantum mechanical account of how consciousness, per se, becomes causally effective is described in sections 7 and 8. It does not “bring the...mental causes fully into the physical world” but rather brings only the effects of the mental causes into the physical world. Searle also has a problem with dualism. He says: “I am rejecting …any form of dualism. Dualism is usually defined as the view that we live in two distinct realms, …the mental and the physical. The problem with dualism is that it amounts to giving up on the central enterprise of philosophy. …It might turn out, for example, that after our bodies are destroyed, our souls or conscious states will float about in a disembodied fashion. But it would be giving up on the philosophical (not to mention scientific) enterprise of trying to explain what we know to be real phenomena if we say that they defy explanation because they inhabit a separate realm.” (p. 19).Stapp argues that a von Neumann process 1 event, which is a completely random
collapse of the wave function, is the physical aspect of a psycho-physical event whose psychologically described aspect is the conscious experience of intending to do, or choosing to do, some physical or mental action. But would this then make the action itself random, raising the standard argument against
free will that if our actions are random, we cannot be free and morally responsible? Stapp wants to only refer to Heisenberg's "free choice" of the experimenter as to what measurement to make.
Mounting empirical evidence suggests that our conscious experiences are connected to brain states in which measurable components of the electromagnetic field located in spatially well separated parts of the brain are oscillating with the same frequency, and in phase synchronization. The model being proposed here assumes, accordingly, that the brain correlate of each conscious experience is an EM (electromagnetic) excitation of this kind. More specifically, each process 1 probing action is represented quantum mechanically in terms of a projection operator that is the quasiclassical counterpart of such an oscillating component of a classical EM field. The central idea of this quantum approach to the mind-brain problem is that each process 1 intervention is the physical aspect of a psycho-physical event whose psychologically described aspect is the conscious experience of intending to do, or choosing to do, some physical or mental action. The physical aspect of the ‘Yes’ answer to this probing event is the actualization, by means of a quantum reduction event, of a pattern of brain activity called a “template for action”. A template for action for some action X is a pattern of physical (brain) activity which if held in place for a sufficiently long time will tend to cause the action X to occur. The psycho-physical linkage between the felt conscious intent and the linked template for action is supposed to be established by trial and error learning. A prerequisite for trial and error learning of this kind is that mental effort be causally efficacious in the physically described world. Only if conscious choices and efforts have consequences in the physically described world can an appropriate correlation connecting the mental and physical aspects of events be mechanically established by trial and error learning. With no such connection the physical action could become completely disconnected from the associated conscious intent with no adverse consequences. The feature of quantum mechanics that allows a person’s conscious choices to influence that person’s physically described brain process in the needed way is the so-called “Quantum Zeno Effect”. This quantum effect entails that if a sequence of very similar process 1 probing actions occur in sufficiently rapid succession then the affected component of the physical state will be forced, with high probability, to be, at the particular sequence of times ti at which the probing actions are made, exactly the sequence of states specified by the sequence of projection operators Ph(t1) that specify the ‘Yes’ outcomes of the sequence of process 1 actions. That is, the affected component of the brain state --- for example some template for action --- will be forced, with high probability, to evolve in lock step with a sequence of ‘Yes’ outcomes of a sequence of “freely chosen” process 1 actions, where “freely chosen” means that these process 1 actions are not determined, via any known law, by the physically described state of the universe! This coercion of a physically described aspect of a brain process to evolve in lock step with the ‘Yes’ answers to a sequence of process 1 probing actions that are free of any known physically described coercion, but that seem to us to be freely chosen by our mental processes, is what will presently be demonstrated. It allows physically un-coerced conscious choices to affect a physically described process that will, by virtue of the basic quantum probability formula, have intended experiential consequences.
Stapp On ChoicesStapp offers helpful new names for John von Neumann's two processes (or dynamical laws). He also adds a third process for the "free choice" of the experimenter. Can he prove we are free by starting with the assumption that this choice is free, or is Stapp being circular? Von Neumann's process 1 is the collapse of the wave function. Since Paul Dirac called this a random "choice by nature," Stapp suggests that we call it Dirac's Choice or the Dirac Process. The Dirac process is random. Von Neumann's Process 2 is the unitary evolution of the wave function according to the Schrödinger equation of motion. Stapp nicely calls this the Schrödinger Process. The Schrödinger process is determined. Stapp then adds a third process to describe what Heisenberg and Bohr called the "free choice" of the experimenter - to decide which experiment to do, which questions to ask of nature. Stapp calls this the Heisenberg Process or Heisenberg Choice. Aristotle would have called the Heisenberg process is up to us. Can we show that is is "free?" Only in the important sense that it is not pre-determined. The big question for Stapp is to understand how a Dirac Choice in the brain can make the decision between alternative possibilities, without making our choices random and denying human responsibility. This is part of the standard argument against free will. If the will is determined, we are not free, If the will is free (random) then we are not responsible. Stapp maintains that the failure of determinism (shown by quantum mechanics) opens the possibility or "free" "choices" and "decisions." This is correct in that our choices and decisions are not pre-determined. He says:
Determinism is the idea that each stage of the coming into being of the physical universe is completely controlled by what has already come into being. A failure of determinism means that what is happening, or coming into being, at certain stages of the evolutionary process is not completely fixed by what has come before. Those aspects of the evolutionary process that are not completely fixed by prior developments can be called "choices" or "decisions". They are in some sense "free", because they are not completely fixed by what has come before. The material universe can no longer be conceived to consist simply of tiny objects similar to small billiard balls, or even things essentially like the electric and magnetic fields of classical physics. Opinions of physicists differ on how best to understand what lies behind the phenomena described so accurately by quantum theory. But the idea most widely accepted by quantum physicists is, I believe, the one of Heisenberg. According to this idea the "material universe" consists of none of the things of classical physics. It consists rather of "objective tendencies", or "potentialities". These tendencies are tendencies for the occurrence of "quantum events". It is these quantum events that are considered to be the actual things in nature, even though the potentialities are also real in some sense. Each actual event creates a new global pattern of potentialities. Thus the basic process of nature is no longer conceived to be simply a uniform mathematically determined gradual evolution. Rather it consists of an alternating sequence of two very different kinds of processes. responsible for his acts has no longer any basis in science... Questioner: You say that a quantum jump selects one of the alternative possibilities, and that this selection is not under the strict control of any known law of nature. And certain of these jumps control the course of brain activity. My question is this: Are not these jumps arbitrary, and if so are we not back in a random universe? Stapp: These jumps are not strictly controlled by any known law of nature. And contemporary quantum theory treats these events as random variables, in the sense that only their statistical weights are specified by the theory: the specific actual choice of whether this event or that event occurs is not fixed by contemporary theory. The fact that contemporary physical theory says nothing more than this does not mean that science will always be so reticent. Many physicists of today claim to believe that it is perfectly possible, and also satisfactory, for there to be choices that simply come out of nowhere at all. I believe such a possibility to be acceptable as an expression of our present state of scientific knowledge, but that science should not rest complacently in that state: it should strive to do better... In this broader context the claim that the choice comes out of nowhere at all should be regarded as an admission of contemporary ignorance, not as a satisfactory final word. Contemporary science certainly allows the choices to be other than "purely random". Indeed, in a model of the quantum world devised by David Bohm these choices are deterministically controlled. The basic question, however, is whether there is a rationally coherent possibility that is both compatible with all scientifically acquired data, yet intermediate to these two alternative possibilities of "pure chance" and "pure determinism". The philosopher A. N. Whitehead speaks of such an intermediate possibility, which is closer to the intuitive idea that our choices are, in some sense, self-determining: namely that they are conditioned by what has come before, yet are not strictly determined by the past, but are nonetheless not without sufficient reason. I think such a possibility is open, but to give this logical possibility a nonspeculative foundation will require enlarging the boundaries of scientific knowledge.The " The first phase is a mathematically controlled evolution of the potentialities for the next quantum event. This first phase is deterministic, and the laws that control it are closely analogous to the laws of classical physics. The next phase is a quantum event. This event is not, in general, strictly controlled by any known physical law, although collections of events exhibit statistical regularities. Thus each individual quantum event creates a new world of potentialities, which then evolves in accordance with certain deterministic mathematical laws. These potentialities define the "tendencies" for the next event, and so on. Each quantum event, because it is not fixed by anything in the physicist's description of prior nature represents a "choice". The critical fact is that each such choice can actualize a macroscopic integrated pattern of activity in the newly created material universe of potentialities. The most important consequence of this altered vision of nature is the place it provides for human minds. Consciousness is no longer forced to be an impotent spectator to a mechanically determined flow of physical events. Conscious events can be naturally identified with certain special kinds of quantum events, namely quantum events that create large-scale integrated patterns of neuronal activity in human brains. These events represent "choices" that are not strictly controlled by any known physical laws. Each such event in the brain influences the course of subsequent events in the brain, body, and environment through the mechanical propagation of the potentialities created by that event. This revised idea of man in relation to nature has profound moral implications. In the first place, it shows that the pernicious mechanical idea of man and nature that arose from seventeenth-century science was dependent upon assumptions that no longer rule science. Contemporary science certainly allows human consciousness to exercise effective top-down control over human brain processes. Hence the idea that man is not two-stage models" of free will put forward by many philosophers and scientists since William James in the 1880's have described a "self-determination" that combines "freely" generated alternative possibilities (for Stapp these are the result of quantum processes in the brain) with an adequately determined "will" that reflects our values, by selecting among the possibilities after evaluating them in accordance with our reasons, motives, feelings, and desires - in short, to be consistent with our character. Here is a diagram of the two-stage model:
The Mohrhoff-Stapp DebateUlrich Mohrhoff reacted to Henry Stapp's 2001 article "Quantum Theory and the Role of Mind in Nature with the claim that it contained 18 errors, primarily the result of misunderstandings or misinterpretations of standard quantum mechanics and its application to mental causation. (See "Mohrhoff on Stapp.") Stapp was generous in answering Mohrhoff's biting criticism with a fine sense of humor. He takes Mohrhoff's 18 error claims as generating a Buddhist "18-fold way" which result in 18 questions with 18 possible right (Yes/No) answers. Stapp worries that he has only one chance in 250,000 of getting the answers all
right (2-18). (See "Stapp on Mohrhoff.") Then take a look at a critical comparison of their questions and answers. See "The Mohrhoff-Stapp Debate."
Excerpts from Mind, Matter, and Quantum MechanicsFrom A Quantum Conception of Man, pp.210-212. The focus of our interest here is on the relationship between the mental and material parts of nature. Human beings have an intuitive feeling that their bodies are moved by their thoughts. Thus it is natural for them to imagine that thoughts of some similar kind inhabit heavenly bodies, rivers and streams, and myriads of other moving things. However, the key step in the development of modern science was precisely to banish all thoughtlike things from the physical universe, or at least to limit severely their domain of influence. In particular, Descartes, in the seventeenth century, divided all nature into two parts, a realm of thoughts and a realm of material things. and proposed that the motions of material things were completely unaffected by thoughts throughout most of the universe. The only excepted regions. where thoughts were allowed to affect matter, were small parts of human brains called pineal glands: without this exception there would be no way for human thoughts to influence human bodies. But outside these glands the motions of all material things were supposed to be governed by mathematical laws. Carrying forward the idea of Descartes, Isaac Newton devised a set of mathematical laws that appeared to describe correctly the motions of both the heavenly bodies and everything on earth. These laws referred only to material things, never to thoughts, and they were complete in the sense that. once the motions of the material parts of the universe during primordial times were fixed, these laws determined exactly the rest of eternity. Although Newton's laws were expressed as rules governing the motions of atoms and other tiny bits of matter, these laws were tested only for large objects, such as planets, cannon balls, and billiard balls, never for atoms themselves. According to Descartes's original proposal the purely mechanical laws of motion must fail to hold within our pineal glands, in order for our thoughts to be able affect our bodily actions. However, orthodox scientists of the eighteenth and nineteenth centuries, tolerating no exceptions to the laws of physics, held that each atom in a human body, or in any other place, must follow the path fixed by the laws of physics. This rigid enforcement of the physical laws entailed, of course, that men's thoughts could have no effects upon their actions: that each human body, being composed of preprogrammed atoms, is an automaton whose every action was predetermined, long before he was born, by purely mechanical considerations, with no reference at all to thoughts or ideas. This conclusion, that human beings are preprogrammed automata, may sound absurd. It contradicts our deepest intuition about ourselves, namely that we are free agents. However, science, by pointing to other situations where intuition is faulty, or dead wrong, was able to maintain, on the basis of its demonstrated practical success and logical consistency, that its view of man was in fact the correct one, and that our feeling of freedom is a complete illusion. This picture of man led, during the eighteenth and nineteenth centuries, to an associated moral system. It was based on the principle that each of us, being nothing but a mechanical device, automatically pursues his calculated self-interests, as measured by a certain bodily physical property, which is experienced in the realm of thought as pleasure. This principle, which was in line with the commercial temper of the times, was fundamentally hedonistic, though, from the scientific viewpoint, realistic. However, philosophers were able to elevate it to a more socially satisfactory idea by arguing that the "enlightened" rational man must act to advance his own "enlightened" self-interest: he must act to advance the general welfare in order to advance, in the end, his own welfare. Yet there remained in the end only one basic human value: no noble, heroic, or altruistic aim could have any value in itself; its value must be rooted in the common currency of personal pleasure. This kind of morality may seem to be immoral but it appears to be the rational outcome of accepting completely the mechanical or materialistic view of man. This view of man and morals did not go unchallenged. Earlier traditions lost only slowly their grip on the minds of men, and romantic and idealistic philosophies rose to challenge the bondage of the human spirit decreed by science. From the ensuing welter of conflicting claims, each eloquently defended, followed a moral relativism, where every moral viewpoint was seen as based on arbitrary assumptions. This pernicious outcome was a direct consequence of the schism between the mental and material aspects of nature introduced by science. That cleavage, by precluding any fully coherent conception of man in nature, made every possible view incomplete in some respect, and hence vulnerable. In the resulting moral vacuum the lure of material benefits and the increasing authority of science combined to insinuate the materialistic viewpoint ever more strongly into men's thoughts. This science-based creed contains, however, the seeds of its own destruction. For behind a facade of social concern it preaches material self-aggrandizement. We are now in the thralls of the logical denouement of that preaching. With the accelerating disintegration of the established cultural traditions, brought on by increased fluxes of peoples and ideas, the demand for satisfaction of inflated material desires has spiraled out of control. This has led to a plundering of future generations, both economically and ecologically. We are now beginning to feel the yoke laid upon us by our predecessors, yet are shifting still heavier burdens onto our own successors. This materialist binge cannot be sustained. Yet the doctrine of enlightened self-interest has no rational way to cope with the problem, as long as each human "self" continues to be perceived as a mere bundle of flesh and bones. For if we accept a strictly materialistic way of thinking, then our own pleasure can be enhanced by ignoring calamities that we ourselves will never face. Men are not base creatures: all history shows them to be capable of elevated deeds. But elevated deeds and aspirations spring from elevated ideas, and today all ideas, if they are long to survive, must stand up to withering scrutiny. They must in the end be rationally coherent, and consistent with the empirical evidence gathered by science. The mechanical ideas of seventeenth-century science provided no rational or intellectual foundation for any elevated conception of man. Yet the ideas of twentieth-century science do. Quantum theory leads naturally to a rationally coherent conception of the whole of man in nature. It is profoundly different from the sundered mechanical picture offered by classical physics. Like any really new idea this quantum conception of man has many roots. It involves deep questions: What is consciousness? What is choice? What is chance? What can science tell us about the role of these things in nature? How does science itself allow us to transcend Newton's legacy? It is to these questions that we now turn. Societal Ramifications of the New Scientific Conception of Human Beings, pp.265-272. A major revolution occurred in science during the twentieth century. This change leads to a profound transformation of the scientific conception of human beings. Whereas the former conception of man undermines rational moral philosophy, the new one can buttress it. I intend to explain here this tectonic shift in science, and its relevance to our lives. I begin by listing three huge turnabouts in science that occurred during the past four centuries. I shall describe how each of them radically transformed our scientific understanding of human beings, and will then spotlight the moral, social, and philosophical significance of these developments. I then conclude by describing practical measures for promoting a rapprochement of science and moral philosophy. The first of the three great shifts was the creation of what is called "classical physics". This development was initiated during the seventeenth century by Galileo, Descartes, and Newton, and was completed early in the twentieth century by the inclusion of Einstein's theories of special and general relativity. The second major shift was the creation of quantum theory. This revision began at the outset of the twentieth century with Max Planck's discovery of the quantum of action, and was completed in the years 1925 to 1927, principally by Heisenberg, Bohr, Pauli, Dirac, Schrödinger, and Max Born. The third crucial shift was the integration of the mental and physical aspects of nature. It was begun in the early 1930s by John von Neumann and Eugene Wigner, and has developed rapidly during the past decade. Each of these three developments has a main theme. The main theme of classical physics is that we live in a clocklike universe, and that even our bodies and brains are mechanical systems. The theory asserts that nature has a "material" part that consists of tiny localized bits of matter, and that every motion of each of these minute material elements is completely determined by contact interactions between adjacent material elements. This material part of nature includes our bodies and our brains. Hence, according to classical physics, each of our bodily actions is completely fixed by mechanical processes occurring at atomic or subatomic levels. Classical physics accommodates the existence also of another part of nature, which consists of our human thoughts, ideas, feelings, and sensations. However, the existence of these experiential aspects of nature is not entailed by the principles that govern the behavior of material parts. The classical-physics framework, which purports to specify completely the motion of every bit of matter, contains no requirement for any experiential aspect of nature to exist at all: the principles of classical physics fail to entail the existence of the defining characteristics of experiences, namely the way that they feel. Since, within the classical framework, our experiences need not even exist, they cannot, within that framework, be the causes of any physical action: our thoughts are reduced to at most passive bystanders. They are not elements of the chain of events that are, within that theory, the necessary and sufficient causes of every material motion, and hence of every bodily action. This causal irrelevance of our thoughts within classical physics constitutes a serious deficiency of that theory, construed as a description of reality. Such an inertness of thoughts, if it were actually true, would mean that reality has experiential parts that have no logically required dynamical link to the physical world that the theory describes: nature would be split into two effectively independent parts. Such a separation is philosophically repugnant. But, besides that, it fails to explain your direct knowledge that you can, by your willful effort, cause your thumb to move. No such effect of mind on matter is explained by the supposedly causally complete classical physics: the felt effectiveness of your thoughts in influencing your bodily actions becomes merely a strange illusion. But how can a rationally coherent moral philosophy be based on a conception of nature in which the thoughts of a normal human being have no effect upon what he does? This difficulty has, quite rightly, been the topic of intense philosophical interest and effort for over three hundred years, but no satisfactory explanation has been found. A second problem with this classical-physics conception of man is the difficulty in understanding the close correlation between brain process and conscious process in the context of the evolution of our species: if there were no causal feedback from conscious process to brain process, then creatures with normal mind—brain correlations would be no better off than organisms with totally disconnected minds and brains. Natural selection would not favor creatures whose ideas about where food is located are correlated to where food is actually located over creatures that always think food is behind them. During the twentieth century this classical theory of nature was found to be incompatible with the emerging empirical data pertaining to the detailed properties matter. A new approach, called quantum theory, was devised. It explains both all the empirical facts that are explained by classical physics, plus all of the newer experimental data in which the classical predictions fail. The new theory differs profoundly from its predecessor. Classical physics was a deterministic theory about postulated localized bits of matter, whereas quantum theory is a probabilistic theory about nonlocalized bits of information. This great step forward was initially bought at a heavy price: scientists had to renounce, in principle, their traditional goal of seeking the "truth" about what was going on in the physical world. They were forced to retreat to the position of being satisfied with a set of practical rules that allowed them to make statistical predictions about connections between their empirical observations, renouncing all claims to any understanding of what was actually going on. This essentially subjective approach to physical theory was devised and promulgated by Niels Bohr, and the physicists that he gathered about him in Copenhagen. Hence it is known as the "Copenhagen interpretation". It works exceedingly well in actual practice. In spite of the unparalleled practical success of the restricted program, some scientists have been unwilling to abandon the ideal that science should strive to find a rationally coherent conception of the reality that lies behind the empirical facts. The only successful effort in this direction that I know of is the one initiated by John von Neumann and Eugene Wigner. It accepts as real the subjective elements of experience that are the basic elements of Copenhagen quantum theory, and relates them to an equally real, but nonmaterial, objective physical universe. Under the impetus of the rapidly growing scientific interest in the connection between the objective and subjective aspects of nature the von Neumann–Wigner approach has been developed over the past decade into a post-Copenhagen quantum theory that explains a great deal of the detailed structure of the emerging data in this field. This development allows quantum theory to be elevated from a set of practically successful—but mysterious—rules, to a rationally coherent conception of man and nature. The basic theme of both Copenhagen and post-Copenhagen quantum theory is that the physical world must be understood in terms of information: the "tiny bits of matter" that classical physics had assumed the world to be built out of are replaced by spread-out nonmaterial structures that combine to form a new kind of physical reality. It consists of an objective carrier of a growing collection of "nonlocalized bits of information" that are dynamically related to experiential-type realities. Each subjective experience injects one bit of information into this objective store of information, which then specifies, via known mathematical laws, the relative probabilities for various possible future subjective experiences to occur. The physical world thus becomes an evolving structure of information, and of propensities for experiences to occur, rather than a mechanically evolving mindless material structure. The new conception essentially fulfills the age-old philosophical idea that nature should be made out of a kind of stuff that combines in an integrated and natural way certain mind-like and matter-like qualities, without being reduced either to classically conceived mind or classically conceived matter. This new quantum structure entails the validity of all the scientifically validated empirical data, while at the same time explaining how our thoughts can influence our actions in a way concordant with our normal experience of that connection. Another pertinent property of the new theory concerns "locality". Classical dynamics is "local" in the sense that all causation is via contact interaction between neighboring bits of matter. Von Neumann—Wigner quantum theory violates that condition in two different ways. The first pertains to the mechanism by which a person's thoughts influence his actions. That process is not a local process in which tiny elements act upon their neighbors. It is a process involving bits of information that reside in space-time structures that can extend over large portions of the person's brain or body, and that are associated with whole experiences. Von Neumann has given a name to this important nonlocal process: he calls it Process I. There is also a second way in which the action of subjective experiences upon the physical world turns out to be "nonlocal": what a person decides to do in one place can instantly influence what is true in distant places. That feature seems, on the face of it, to contradict the theory of relativity, which forbids sending signals faster than light. However, quantum theory is exquisitely constructed so that all of the empirically testable consequences of the theory of relativity are preserved. But, in spite of this restriction, the picture of nature that emerges is one in which the global evolution of the universe is controlled in part by choices made by localized agents, such as human beings. The causal roots, or origins, of these choices are not specified by any laws that we yet know or understand. In that very specific sense these choices are "free". However, they can affect the behavior of the agent himself, and necessarily have, moreover, effects on faraway physical events. What are the moral, social, and philosophical implications of this profound revision of our scientific understanding of man and nature? There has been a long-standing conflict between classical physics and rational moral philosophy: according to the precepts of classical physics each man is a machine ruled by local material processes alone, whereas rational moral philosophy is based on the presumption that what a normal human being knows and understands can make a difference in how he behaves. Jurisprudence is, accordingly, based on the premise that insofar as a person was able to know the nature and quality of the act he was doing or to know he was doing what was wrong, then he is responsible for that act. This rule is based on the premise that knowing and understanding can influence behavior. But classical physics, by claiming all behavior to be completely determined by atomic or subatomic processes that do not entail the existence of knowing or understanding, undermines that premise. It would make no sense to make responsibility hinge on knowing and understanding if knowing and understanding cannot influence action. One must place responsibility where power lies. Quantum theory, unlike classical physics, allows a person's mental process to make a difference in how his body behaves. Von Neumann quantum theory injects human thoughts into the causal structure of nature in an irreducible way that allows a person's mental effort to influence his bodily actions. This influence of mind is not just a redundant re-expression of other known or postulated laws, but is an effect that has no other known cause. The situation is this: Quantum theory dynamics is like "twenty questions". First some definite question with a Yes or No answer is chosen. Then nature delivers an answer, Yes or No. The relative probabilities of the two possible answers, Yes and No, are specified by the theory, and are therefore not controllable by human beings. But both Copenhagen and post-Copenhagen quantum theory allow an "agent" to choose which question will be asked. These choices are, in general, not specified by any known laws of physics. They are in this very specific sense "free choices". But these choices can, according to the known laws of quantum theory, influence the physical behavior of the agent. Thus twenty-first-century science, unlike nineteenth-century science, does not reduce human beings to mechanical automata, deluded by the scientifically unsupportable belief that their thoughts can make a difference in how they behave. Rather it elevates human beings to agents whose "free choices" can, according to the known laws, actually influence their behavior. The problem with classical physics is not just some airy philosophical abstraction. The philosophical dilemma has trickled down into the workings of our society. The Australian supreme court justice David Hodgson has written a book, The Mind Matters, that documents the pervasive and pernicious effect that the idea that "mind does not matter" is having upon our legal system. An example occurred in San Francisco: Dan White walked into the office of Mayor George Moscone and shot him dead, and then walked down the hall and shot dead Supervisor Harvey Milk. White got off with five years, on the basis of the infamous "twinkie defense" that he was not responsible for his actions, owing to derangement caused by junk foods. One of the most influential philosophers of the present time, Daniel Dennett, argues in his book Consciousness Explained, and elsewhere, that our conscious thoughts, as we normally understand them, do not exist, and ought to be drummed out of our scientific understanding of human beings. He explained his basic motivation: If this claim were indeed true, then Dennett's conclusions might be valid. But the clear message of the quantum theory is that Dennett's assumption is not valid: what a person's brain does can, according to the quantum theory, be strongly influenced by a nonlocal causal process connected to the person's conscious choices and mental efforts. Consciousness can play a nonredundant causal role in the determination of our actions: it can play the very role that we intuitively feel that it plays. Quantum theory allows your mind and your brain to co-author your physical actions. A central moral issue concerns "values". What a person values depends, basically, on what he believes himself to be. If he believes that he is an isolated hunk of protoplasm, struggling to survive in a hostile world, or a physical organism constructed by genes to promote their own survival, then his values will tend to be very different from those of a person who regards himself as a being with a mind-like aspect that makes conscious choices that control in part his own future, and are also integral parts of the global process that generates the unfolding of the universe. The second half of the twentieth century featured the rise of postmodernism. It denies the relationship between discourse and reality, and claims that "what we think we know" is just "what we have been discursively disciplined to believe". This abandonment of the idea of objective truth leads directly to moral relativism. It draws support both from the theory of relativity, which proclaims that what is true about nature depends upon the observer, and from the Copenhagen philosophy that renounces, even in science, the search for objective truth. But post-Copenhagen quantum theory sees the Copenhagen rejection of all inquiry about the nature of reality as merely a transitory phase between the old classical conception of reality to a more unified contemporary conception of nature. But this profound shift in what science says about the nature of the physical world, and of human beings, has yet to sink into the public consciousness. One thing that needs to be done to resuscitate moral philosophy is to infuse into the intellectual milieu an awareness of the important relevant changes wrought by quantum theory in our understanding of the nature of man. This initiative would involve the introduction into curricula, at all levels, of the contemporary quantum conception of nature in terms of information. False mechanistic ideas inculcated into tender minds at an early age are hard to dislodge later. If our children are taught that the world is a machine built out of tiny material parts, then both science and philosophy are damaged. The progress of science is inhibited by imbuing young minds with an incorrect idea of the nature of reality, and the pernicious philosophical idea that man is made of classically conceived matter is not exposed as being incompatible with the empirical facts. One might think that the ideas of quantum physics are too counterintuitive for young minds to grasp. Yet students have no trouble comprehending the even more counterintuitive classical idea that the solid chairs upon which they sit are mostly empty space. Children and students who, through their computers, deal all the time with the physical world conceived of as a repository and transmitter of information should grasp far more easily the quantum concept of the physical world as a storehouse and conveyor of information than the classical concept of physical reality as a horde of unseen particles that can somehow be human experience. A thoroughly rational concept into which one's everyday experiences fit neatly should be easier to comprehend than a seventeenth-century concoction that has no place for one's own being as an active agent with efficacious thoughts, a concoction that has consequently confounded philosophers from the day it was invented, and which has now pushed some philosophers to the extremity of trying to convince us that consciousness, as we intuitively understand it, does not exist, or is an illusion, and other philosophers to the point of making truth a purely social construct. In order to free human beings from the false materialist mind-set that still infects the world of rational discourse, a serious effort is needed to move people's understanding of what science says out of the seventeenth century and into the twenty-first. One problem stands in the way of pursuing this updating of the curricula. Most quantum physicists are interested more in applications of quantum theory than in its ontological implications. Hence they often endorse the "Copenhagen" philosophy of renouncing the quest to understand reality, and settling, instead, for practical rules that work. This forsaking by physicists of their traditional goal of trying to understand the physical world means that there is now no official statement as to the nature of reality, or of man's place within it. Still, I believe that there will be near-unanimous agreement among quantum physicists that, to the extent that a rationally coherent conception of physical reality is possible, this reality will be informational in character, not material. For the whole language of the quantum physicist, when he is dealing with the meaning of his symbols, is in terms of information, which an agent may or may not choose to acquire, and in terms of Yes-or-No answers that constitute bits of information. Just getting that one idea across could make a significant inroad into the corruptive materialist outlook that, more than three-quarters of a century after its official demise as a basic truth about nature, still infects so many minds.