Gilbert Ryle’s logical behaviorism that we explored in the previous section is actually a form of physicalism, since the theory holds that there is no immaterial self that exists independently of one’s body or visible behavior. But, as we saw, there are serious problems with this particular view. Brand Blanshard’s devastating critique of behaviorism’s equating of the self with bodily behavior is punctuated with the indelible image of a behaviorist whose headache is defined in terms of a set of behaviors: grimacing, clutching one’s head, and so on. Although behaviorism remained an influential movement in modern psychology for much of the twentieth century, most philosophers abandoned it as a viable model of the self. However, with the advent of computers, some philosophers saw an opportunity to recast the behaviorist model in a new form that would avoid the conceptual inadequacy of defining the self solely in terms of a person’s observable behavior, while at the same time retaining some of behaviorism’s advantages. What advantages? First and foremost, as a form of physicalism, behaviorism made it possible to avoid the dualism of Plato, Augustine, Descartes, and others, the “ghost in the machine” that leaves us wondering exactly how our nonphysical, immaterial self is related to our physical, material self. As the philosopher Jerry Fodor* notes in an essay entitled “The Mind–Body Problem,”

In other words, a dualistic perspective on the mind–body situation leaves us with a profoundly unscientific view of the self. In contrast, behaviorism’s approach, denying the immaterial, unobservable self, makes it possible for scientists to observe and experiment with the behavior that is thought to define the self and the sensory stimulants that give rise to the behavior.

Using computers as a model of human functioning, a new school of thought—“functionalism”—developed. It was a perspective that, like behaviorism, still maintained that the model for the human mind was the connection between sensory stimulation and observable behavior. The difference was that functionalists also acknowledged that there were “mental states” that served to “connect” the sensory stimulation and observable behavior. For functionalism, what makes something a mental state does not depend on its internal constitution, but rather the way it functions, or the role it plays, in the system of which it is a part. Jerry Fodor explains:

Computers serve functionalists as a model of human mental functioning in several ways. To begin with, computers initially operated on an input/output model: certain instructions or tasks are given to the computer, such as a mathematical problem (input), and the computer responds by solving the problem through internal operations and presenting the answer to us (output). Functionalists contend that this is the same basic model for humans: we receive a complex variety of stimuli through our senses (seeing, hearing, smelling, tasting, touching)—“input”—that activate various mental states that ultimately result in observable behavior—“output.” Jerry Fodor provides an example to illustrate this point: ironically, the same “headache” example cited by the behaviorist critic Brand Blanshard:

Analyzing the example of experiencing a headache makes clear the contrast between behaviorism and functionalism. For the behaviorist, the experience is triggered by certain sensory stimuli that lead to behavioral responses associated with a headache: grimacing, clutching one’s head, and so on. In describing this experience, the behaviorist does not make any reference to internal mental states or private conscious experience. The connection between the head-hurting stimulus and the observable responses are entirely public, available for all to see, not just the victim of the headache.

Functionalism provides a more complex analysis of the headache experience. Functionalists still agree with behaviorists that the core thinking connection is between the sensory stimuli and the behavioral responses associated with a headache. What’s different is that the functionalist believes that there are certain mental events, mental activities or mental processes that form the full connection between the sensory stimulus and the observable behavioral response such as:

• the internal head pain that one is experiencing

• the belief that taking aspirin may help reduce this pain

• the intention to take an aspirin in order to relieve the pain

These mental events, activities, and processes then lead the individual to behave in certainly observable ways by doing things like taking an aspirin, stating “I have a headache,” and so on. So for the functionalist, providing a complete analysis of the self means not only identifying the fundamental stimulus-behavioral response connection, but also describing the network of mental states, activities, and processes that are an integral part of the causal connection between the original stimulus and behavioral response.

It’s reasonable to ask the functionalist, “How are the mental states, activities, and processes different from the immaterial dimensions of the mind and self that traditional mind-body dualism advocates?” The functionalist response is that these mental states, activities, and processes are not thought to have an independent existence apart from the function they serve to connect the original stimulus and observable behaviorable response. Using computers again as a model, functionalists contend that while the actual brain is analogous to “computer hardware,” the mental states, activities, and processes are analogous to “computer software.” As with computers, our mental “software” functions as instructions, patterns, logical sequences that enables the original stimulus “input” to be causally connected to the behavioral “output.” Just like computer software is not thought to have an independent nonmaterial “existence” apart from the function that it has within the entire system.

As Fodor notes, one intriguing implication of this view of the human mind as analogous to computer software is that it “recognizes the possibility that systems as diverse as human beings, calculating machines and disembodied spirits could all have mental states. In the functionalist view, the psychology of a system depends not on the stuff it is made of (living cells, metal or spiritual energy) but on how the stuff is put together.”

So is functionalism successful in avoiding the conceptual pitfalls of mind-body dualism while still giving a compelling account of our mental, conscious existence? It’s likely that philosophers on both sides of the mind-body divide will find the functionalist “solution” less than satisfying. On the one hand, for those dualists (and nonreductive physicalists) who believe human consciousness and inner conscious states can not be reduced to and fully explainable in terms of physical processes, the functional existence awarded to mental states, activities, and processes will likely appear weak and limited—not really doing justice to the rich, robust, and very personal life of the mind and consciousness that we experience in such a compelling way.

On the other hand, hard-core physicalists who are convinced that the mind is reducible to or fully explainable in terms of physical brain processes may feel philosophically queasy regarding the quasi-existence accorded by the functionalists to mental states, activities, and processes. One way this critique has been expressed concerns whether functionalism can account for what we take to be the causal efficacy of our mental states. For example, if I am experiencing a headache, the pain of which is the result of a neural state, then why do I need functional mental states (like the pain itself specified in functional terms) to connect the pain stimulus (identified as a brain state) to the response of pain behaviors (such as holding my head and saying “I have a headache”)? Such mental states seem to be causally irrelevant to the entire process, since we can give a complete causal explanation of my behavior without referring to functional mental states. Of course, this is a similar “mental causation” criticism that functionalists have directed towards dualism, as Fodor observes: “If the mind is nonphysical it has no position in physical space. How, then, can a mental cause give rise to a behavioral effect that has a position in space? . . . [H]ow can the non-physical give rise to the physical without violating the laws of the conservation of mass, of energy and of momentum?” In trying to please both the mind-body dualists and the physicalists, it’s possible that functionalism ends up pleasing neither.

Humans have known since recorded history of the close, intimate relationship between the mind and the body. The health of our bodies, the things we ingest, the experiences we endure—all of these dimensions of our physical self have a profound effect on our mental and emotional functioning. Similarly, our emotional states, the way we think about things, our levels of stress, the optimism (or pessimism) we feel—all of these dimensions of our mental self have a dramatic impact on our physical condition. As an example, just consider how the single word heart is used to display this intimate connection between the emotional and the physical: heartfelt, heartache, heartsick, heartened, large-hearted, heartless, lighthearted, hard-hearted, faint-hearted, heartbroken.

Modern science is now able to use advanced equipment and sophisticated techniques to unravel and articulate the complex web of connections that binds consciousness and body together into an integrated self. In fact, one of the most dynamic areas of scientific research currently is that devoted to exploring the mind-brain relationship, and the information being developed is fascinating. Scientists are increasingly able to correlate specific areas in the brain with areas of mental functioning, both cognitively and emotionally. Psychotropic drugs are being developed that can influence emotional states such as depression or extreme social anxiety. Brain scans can reveal physical abnormalities that are related to personality disorders. And discoveries are being made in the reverse direction as well, detailing the physical effects of emotional states such as anxiety, depression, anger, pessimism, and optimism on the health and well-being of the body. The assumption of this approach is that to fully understand the nature of the mind we have to fully understand the nature of the brain.

The impressive success of such scientific mind-brain research has encouraged many to conclude that it is only a matter of time before the mental life of consciousness is fully explainable in terms of the neurophysiology of the brain. The ultimate goal of such explorations is to link the self—including all of our thoughts, passions, personality traits—to the physical wiring and physiological functioning of the brain. Although such thinkers recognize that achieving such a goal will take time, they are confident that we will progressively develop ways of describing the mind, consciousness, and human experience that are physiologically based. The contemporary philosopher Paul Churchland* articulates such a vision in the following essay. He begins by acknowledging that a simple identity formula—mental states = brain states—is a flawed way in which to conceptualize the relationship between the mind and the brain. Instead, we need to develop a new, neuroscience-based vocabulary that will enable us to think and communicate clearly about the mind, consciousness, and human experience. He refers to this view as eliminative materialism.

Churchland’s central argument is that the concepts and theoretical vocabulary we use to think about our selves—using such terms as belief, desire, fear, sensation, pain, joy—actually misrepresent the reality of minds and selves. All of these concepts are part of a commonsense “folk psychology” that obscures rather than clarifies the nature of human experience. Eliminative materialists believe that we need to develop a new vocabulary and conceptual framework that is grounded in neuroscience and that will be a more accurate reflection of the human mind and self. Churchland proceeds to state the arguments that he believes support his position.

Churchland’s point is that the most compelling argument for developing a new conceptual framework and vocabulary founded on neuroscience is the simple fact that the current “folk psychology” has done a poor job in accomplishing the main reason for its existence—explaining and predicting the commonplace phenomena of the human mind and experience. And in the same way that science replaces outmoded, ineffective, and limited conceptual frameworks with ones that can explain and predict more effectively, so the same thing needs to be done in psychology and philosophy of mind. This new conceptual framework will be based on and will integrate all that we are learning about how the brain works on a neurological level.

Although he believes strongly in the logic of his position, Churchland recognizes that many people will resist the argument he is making for a variety of reasons.

Churchland’s ultimate concession that the psychology-based conceptual framework currently used by most academic disciplines and popular culture may not end up being completely eradicated and replaced by a neuroscience framework still operates within his physicalist framework: for those “folk psychology” terms not eliminated will nevertheless be reducible to neurophysical statements of brain states.

Of course, there are many people who believe that there are fundamental differences between the life of the mind and neuroscientific descriptions of the brain’s operation. Many people believe that, no matter how exhaustively scientists are able to describe the physical conditions for consciousness, this does not mean that the mental dimensions of the self will ever be reducible to these physical states. Why? Because in the final analysis, the physical and mental dimensions of the self are qualitatively different realms, each with its own distinctive vocabulary, logic, and organizing principles. According to this view, even if scientists were able to map out your complete brain activity at the moment you were having an original idea or experiencing an emotional epiphany, that neurobiological description of your brain would provide no clue as to the nature of your personal experience at that moment. Articulating and communicating the rich texture of those experiences would take a very different language and logic.

Fascinatingly, it was Socrates who first articulated a coherent critique of the materialist position in Plato’s dialogue Phaedo, during the period following his trial and conviction. Socrates ridicules the materialist position, which he attributes to the philosopher Anaxagoras, which, he says, would explain his decision to remain in Athens by reference to his “bones and sinews,” rather than the result of the conscious choice of his mind. With surprisingly good humor he explains that if it was up to his body he would not have remained in Athens to be executed, but rather “I fancy that these sinews and bones would have been in the neighborhood of Megara or Boeotia long ago—impelled by a conviction of what is best!—if I did not think that it was more right and honorable to submit to whatever my country orders rather than to take to my heels and run away.” In other words, Socrates is arguing that it is his conscious, rational mind that has determined his fate, and attempting to use a materialistic framework to explain his actions makes no sense. “If it were said that without such bones and sinews and all the rest of them I should not be able to do what I think is right, it would be true. But to say that it is because of them that I do what I am doing, and not through choice of what is best—although my actions are controlled by mind—would be a very lax and inaccurate form of expression.” For Socrates, even if we had a complete description of how the body (and by extension the brain) worked, we would still be unable to dispense with folk psychological terms such as choice and belief.

Logical behaviorism, functionalism, eliminative materialism . . . these are all contrasting physicalistic theories of the human self and mind. They all share the fundamental belief that the human mind can be fully understood by understanding and describing the human brain. The philosopher Richard Brown*, of the City University of New York, publishes widely in the philosophy of mind and hosts an annual online conference that centers on the nature of consciousness. In the following essay, Brown provides a brief overview of several theoretical perspectives regarding consciousness, and he describes a number of fascinating “thought experiments” that philosophers sometimes use as vehicles for analysis.