When we think about what’s real, physical objects are at or near the top of the list. Virtually no one doubts the existence of their own bodies, or those of others, or the myriads of material things that crowd around us. A 3-D physical object sitting out there where everyone can see it – my new coffee maker, for instance – can’t be written off as a collective hallucination, or at least not easily. True, a good sophist could probably convince you it doesn’t exist, but let’s set such considerations aside. What’s real, we pretty much all agree, includes what everyone could see, touch, smell, and otherwise detect using their standard sensory and perceptual capacities, were they in range of the object.
This seems to put your subjective experience on a somewhat less secure footing, reality-wise. No one else is in a position to have it and therefore back up your claim that it exists. When you taste the coffee from my coffee maker that taste is a private affair; it’s unequivocally real to you, but for others it’s a matter of trusting your report as truthful. More momentously, if you’re in pain from a back injury and can’t work, then you have to convince the unemployment office that you’re not malingering and need worker’s compensation to tide you over. Skepticism abounds about such claims, so anything you can do to show a bona fide physical source of the pain, for instance an MRI of a compressed spinal disk, is much to your advantage.
Skepticism also still exists in certain quarters about the reality of mental illnesses such as depression and behavioral disorders such as addiction and obesity. Some suppose the “victims” of such disorders could and should simply snap out of it, that they’re making a willful, blameworthy choice to escape social responsibilities or indulge carnal appetites. This is one reason why those suffering from mental illness, addiction (including behavioral addictions such as gambling) and obesity have welcomed scientific findings that show a physical basis for their difficulties, whether in the brain, endocrine system or elsewhere in the body. The experience of being motivationally undone by depression is crushingly real for the patient but is doubted by the skeptic, so evidence for the biological basis for depression is just what the doctor ordered to establish it as a real disease. Relatedly, a recent op-ed in the New York Times on awarding the Purple Heart for combat veterans diagnosed with PTSD said: “A Purple Heart may not be the answer – not until, perhaps, advances in brain science bring full objectivity to the diagnosis of mental injury.” (emphasis added)
These examples illustrate the trend toward physicalism in our self-understanding. What were once considered categorically immaterial mental phenomena are now shown to have a material basis in the nervous system, most notably the brain and its complex array of interconnected neural networks. The behavioral and brain sciences are calling into question the notion that we need appeal to anything beyond or above the brain and body – an immaterial soul, for instance – to explain behavior and experience, whether normal or abnormal. Those who have a stake in the soul, or in some non-physical power of will, find themselves increasingly on the defensive because physicalist explanations have no need of them. Occam’s razor cuts away anything that can’t be shown to play an evidence-based explanatory role in controlling behavior or producing subjective experience. This isn’t to say that physicalist explanations are anywhere near complete, nor does it conclusively disprove the existence of the soul or some other immaterial aspect of ourselves – nothing could do that. But it is to say that as physicalism makes headway, the dualist hypothesis that the mind is categorically independent of the brain in some respect has less and less going for it.
A recent Boston Globe story on fatigue, Way too tired, conveys nicely the impact of physicalism on judgments about what’s real:
Scientists are now convinced that fatigue has a real, molecular basis, and that at least two major biological processes are involved: An excess of natural chemicals called pro-inflammatory cytokines, which the body pumps out in response to infection. And sluggish mitochondria, the tiny organelles inside cells that make energy. (emphasis added)
That fatigue is now seen to have “a real, molecular basis” in the brain and body helps to support the judgment that it’s incontestably real in the way that other physical things are – it isn’t a possibly illusory or conjured up feeling that’s “just in the head” in the old sense of that expression. Fatigue is a bodily, material phenomenon that happens to have a subjective correlate, the experience of fatigue. Likewise, if you experience fatigue, there’s a physical correlate somewhere in the brain and body without which you wouldn’t be experiencing it. According to this picture, to “snap out” of being fatigued would require a sudden change or override of that physical state, unlikely but not an impossibility (you win the lottery, in the excitement your fatigue is temporarily alleviated). But it certainly doesn’t involve the exercise of some immaterial will power independent of the brain and body.
News stories on drug addiction, gambling and obesity increasingly cite scientific findings about the neural basis of behavior and their effect on attitudes and approaches to treatment. For example, a recent Time article on overcoming addiction says:
…because of the way the brain is wired, each time an addict lets an urge pass without engaging in the unwanted behavior, it weakens the neural connections that underlie the desire; each time he or she rewards the craving with the bad habit, the brain pathways, and the addiction, are strengthened. It helps for people to remind themselves that if they can resist an addictive urge once, it will become easier and easier to do it again in the future.
Not only are addictive urges described as being dependent on brain states, the physicalist picture is used to give the addict encouragement: if you resist an urge, that has a real, physical effect on neural connections which will make future urges easier to resist. Behavior (resisting an urge) directly affects the brain which in turn affects behavior, so there’s no need or reason to appeal to anything immaterial. In particular, the addict or over-eater isn’t charged with mustering a power of will that’s imagined to be independent of her situation, whether internal (her brain and body) or external (her social and physical environment). Instead, the power to resist an urge is seen as a function of her total situation. This means that giving in to an urge can’t be chalked up to the failure to exert one’s immaterial will – there is no such thing – which helps to reduce the stigma and blame so often attached to addiction and obesity. Moreover, a physicalist understanding gives clients and clinicians greater power and control, since they have a clear causal picture of compulsive behavior which can be leveraged into effective treatments.
Awareness of the neural basis of behavioral disorders has helped to generate support for parity between mental and physical illnesses in medical insurance coverage. Mental illnesses and addictions are, the neuroscientific evidence shows, just as physically real as other illnesses, it’s just that their basis in the brain is not immediately accessible to public observation, as is a broken leg. Since they are just as real, they merit equal coverage for treatment.
Now, why would anyone (besides insurance companies, perhaps) have a problem with this development, or more generally with physicalism? One reason is that in the West we’re strongly attached to the idea that we are immaterial in some respect, that there’s got to be something in us that isn’t “merely” physical. After all, it certainly feels to many folks as if there’s an immaterial mental me inside, and that me is often thought to be in charge, the non-physical boss of the brain and body that can exert its will as it likes, independent of its physical circumstances. Being told there is no such thing, although it might help destigmatize addiction, obesity and mental illness, is not exactly what people want to hear. If there’s no boss, just the brain doing its thing, then who or what do we hold responsible? Don’t we then become organic robots at the mercy of the brain’s neural whims, and puppets of fate, determined in our every thought and action? Can’t we just tell the judge, “Your honor, my brain made me do it”?
This worry, what we might call neuro-existentialist anxiety (following philosopher Owen Flanagan), unquestionably impedes acceptance of physicalism and more broadly naturalism, but I won’t address it here since it’s the focus of many articles at Naturalism.Org. Suffice it to say that a healthy brain does an excellent job, all on its own, of controlling behavior, thinking thoughts, planning ahead, and making morally informed choices. We don’t need to be immaterial souls with contra-causal free will to be held responsible and be effective agents, and even though consciousness probably doesn’t serve a command function over and above what its neural basis accomplishes, we are still conscious, and that continues to matter (see Holding mechanisms responsible). The humanitarian goal of minimizing suffering should still be among our top priorities in a world without souls.
But even if we can reassure folks that they’re managing perfectly well without the soul and its kernel of unconditioned freedom, there are other sources of resistance to physicalism. Some conservative critics of progressive social policy want to maintain the fiction that persons do have a power of choice independent of their brain, body and situation. Why? Because it helps to justify small government and laissez-faire: people’s free will can always trump or circumvent any interventions designed to help them, so interventions are of limited value. Besides, individuals could just choose to behave properly, whatever their material or psychological circumstances, so they don’t need much government or medical assistance. The assumption of free will also helps to justify punitive policies based on the idea of radical personal responsibility and autonomy: since disordered behavior, such as compulsive gambling or over-eating, is ultimately up to you-the-immaterial-controller, not your brain, body and situation, all of which are traceable to prior circumstances, you deserve punishment for making bad choices, certainly not help. (See here for more on social policy and free will.)
This might seem a bit of a stretch. Do some conservatives (not all, of course) really take such a hard line? As it turns out, professor of rhetoric and communication Richard Vatz and psychologist Jeffrey Schaler argue against parity for mental health and addictions treatment on just these grounds (in an October 23, 2008 op-ed for the Baltimore Sun, Parity through the back door):
Substance disorders are arguably a function of behavioral choices and in no way constitute diseases to which insurance should apply. Such self-destructive behavior is best explained by mindset, personal values and how a person copes with his or her environment. Incidence varies by cultural context, and people can clearly stop or control their addictions through an exercise of free will. Not so when it comes to bodily illness; one can no more will away cancer, heart disease or diabetes than he or she can will their onset.
They believe, in other words, that the addict could simply will her way out of addiction, but simply chooses not to. Therefore we’re not dealing with a treatable disease or disorder legitimately covered by insurance, but a moral failure that deserves stigmatization. And, no surprise, they endorse stigma as a policy:
Supporters of parity celebrate the new law as signaling the end of "stigma," but they fail to consider that stigmatization is a marvelous negative reinforcer for undesired behavior, some of which is called "mental illness."
It’s true that stigma, shame and other negative reinforcers (that is, punishments) sometimes reduce the incidence of undesired behavior, at least temporarily. Whether they are deserved in the sense Vatz and Schaler suppose they are – for not having exercised one’s free will – is another story. If they are not, that’s a good reason to use non-punitive and more effective means of behavior change, not to mention that such alternatives don’t inflict collateral damage on those already beaten down by addiction and other behavioral disorders. (Their op-ed is also critiqued here very effectively by Daniel Guarnera.)
Vatz and Schaler’s argument illustrates what hangs on the dispute between dualism and physicalism. If addiction and many “so-called” or “supposed” (as they put it) mental illnesses aren’t real, brain-based disorders, but freely willed choices that are independent of one’s bio-psycho-social conditions in some crucial respect, they should be punished and stigmatized, not treated. Those making such choices should suffer the deserved effects of their morally culpable decision to become and remain addicted, overweight, depressed, etc. This punitive, dualistic moral model is in sharp contrast with the naturalistic medical model of behavioral disorders and mental illness, which as we’ve seen accepts their physical reality and their causal roots in the sufferer’s biological endowment, environmental history and current circumstances. As such, it seeks to treat the condition, whatever its severity, and minimize suffering, not punish.
This is the moral and practical significance of physicalism: that by medicalizing what were once thought to be failures of will, the physicalist understanding of mental illness and behavioral disorders helps to de-stigmatize them and points the way to effective treatment. Understanding the causal pathways in the brain and the causal connections between the person and environment gives rise to compassion and control.
This isn’t to deny that there’s a moral component to some of these disorders when, like addiction, they involve voluntary, intentional behavior that we properly judge to be wrong (e.g., stealing and cheating to pay for alcohol and other drugs). But in making this judgment, we don’t suppose that given her situation the addict could have done otherwise – she doesn’t have contra-causal free will. This helps to undercut vindictive and punitive attitudes, and reinforces the humanitarian constraint on treatment: that “negative reinforcers” are applicable only if there’s no non-punitive alternative for controlling or changing behavior, and only if they produce a benefit that clearly outweighs their harms and risks. If an addict or someone with mental illness breaks the law, then legal sanctions apply, but in a humane and consequentialist (as opposed to retributivist) criminal justice system those sanctions would take the disorder fully into account at sentencing, referring those with treatable conditions to appropriate facilities.
Some of those attached to placing blame as the preferred response to mental illness and behavioral disorders will, like Vatz and Schaler, defend the reigning dualist conventional wisdom that people have contra-causal free will. They will insist that we all have the capacity to rise above the total net sum of our circumstances, if we would only choose to exercise it. But, if they want science on their side, they must demonstrate the empirical, intersubjectively available evidence for its existence and an explanation of how it works, both of which are thus far notably lacking (despite the claims of some vociferous anti-materialists, see note 2). Absent good evidence and explanation, they will appeal to widespread dualist intuitions and to common fears about the supposed perils of physicalism mentioned above. But neither a view’s popularity nor its imagined dangers count for anything when assessing its truth, and neuroscience is gradually closing the explanatory gaps where the soul and its supernatural freedom could reside. So the prospects for a coherent dualism that could support the non-reality of mental illness and addiction are not good. The conservative, sober, responsible conclusion to draw, given the available evidence, is that they are physically real.
Some might worry that physicalism impugns the reality of subjective experience, or of human rationality, but it does not. It only claims that good explanations of consciousness, subjectivity, intelligence and reason will likely involve nothing spooky or ectoplasmic, that is, nothing that transcends or contravenes the known laws of nature. The very tight correlation of subjective experience and mental activity such as moral decision-making with brain states makes this prediction plausible, even if a transparent, easily graspable explanation of consciousness as a brain-based phenomenon still eludes us. Now, science can’t and shouldn’t rule out the possibility that a categorically non-physical realm of entities, processes and properties exists that somehow interacts with the physical realm. Should good empirical evidence come to light supporting such categorical dualism, so be it. But for the time being we should proceed on the plausible assumption that consciousness, reasoning and the capacity for voluntary choice all depend completely on the material substrate of the brain as it’s shaped by the interaction of internal and external factors, including our very own actions. That assumption is not only very likely true, it supports humane and effective approaches to mental illness and behavioral disorders.
TWC, January 2009
 For instance among scientologists and professional skeptics such as Thomas Szasz and Jeffrey Schaler (see below). For a good critique of Szasz and an insightful analysis of the concept of objectivity, see Ron Pies’ Objectivity in mental health: who has a real disease?
 See A little effort goes a long way: “Not willpower, but 'habit change' is the new key to weight loss” and Fast food may be addictive: “New and potentially explosive findings on the biological effects of fast food suggest that eating yourself into obesity isn't simply down to a lack of self-control. Some scientists are starting to believe that bingeing on foods that are excessively high in fat and sugar can cause changes to your brain and body that make it hard to say no.”
 See Congress, Bush approve addiction and mental health parity legislation at Join Together Online.
 Providing reassurance is a primary occupation of those promoting naturalism; see for instance Three strikes against fatalism, Avoiding demoralization by determinism, Misrepresenting naturalism, and The viability of naturalism.