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Part II
Empirical Evidence

Chapter 3
An Overview of the Empirical Evidence

Readers familiar with the subject of faith healing may find references to some of the best-known faith healers, e.g., the seventeenth-century healer Valentine Greatrakes, conspicuously absent here. The reason for this is that most of these healers derived their fame from their ability to heal others, which renders their major achievements psychokinetic and beyond the scope of this project. Nevertheless, there is no shortage of empirical evidence on the psychosomatic side, as this and the following five chapters should demonstrate.

I. Organizing the Evidence

The body of empirical evidence in support of psychosomatic healing is voluminous. I have chosen to divide the discussion of the evidence presented in Part II into six chapters:

  1. An Overview of the Empirical Evidence
  2. Evidence from the Placebo Effect
  3. The Nascent Science of Psychoneuroimmunology
  4. Controlled Statistical Studies of Mental Healing
  5. Documented Evidence for Psychosomatic Causation

In Chapter 3 (the present chapter), I identify what I consider to be bona fide evidence and the criteria by which it is included. Four chapters that present the evidence itself follow.

Evidence from the Placebo Effect (Chapter 4). This is the phenomenon of healing via a drug or other remedy that the patient believes is efficacious, when in fact the remedy itself is not. The classic example of a placebo is a sugar pill given to someone who has been told he or she is receiving a miracle drug. The placebo effect occurs when the mere belief in the remedy renders the remedy effective. It is one of the most extensively documented and widely accepted forms of mental healing. In fact, it may be the only one that mainstream medical research has fully acknowledged. For example, in attempting to prove a new drug effective, researchers conduct "double-blind" studies, in which neither the recipients nor the administrators of the experiment know who is getting the placebo and who is getting the real thing -- in order to prevent the placebo effect from invalidating the test.

The Nascent Science of Psychoneuroimmunology (Chapter 5). In recent years, medical researchers have discovered that the nervous, endocrine, and immune systems all interact with one another, suggesting that the brain may be involved in healing. As we shall see later in this essay, psychoneuroimmunology is a double-edged sword for advocates of mental healing. Although it tells us the role of the central nervous system in healing, it does not tell us if or how thoughts can move gray matter.

Controlled Statistical Studies of Mental Healing (Chapter 6). There are also many controlled studies verifying the effects of one's thinking -- both constructively and destructively -- on one's health. In this chapter, I review a sample of these studies. Some deal with the overall effect of thought processes on health. Others deal specifically with heart disease and cancer, the first of which takes more American lives than all other diseases combined.(11) I also cite a documented case study indicating that AIDS may be subject to mental cure or at least regression.

Documented Evidence for Psychosomatic Causation (Chapter 7). This chapter presents individual cases and experimental evidence demonstrating the extraordinary ways in which thinking can affect the body. Although little of it deals with mental healing per se, it does render the phenomenon of mental healing more plausible. Included in this section are biofeedback experiments and documented case studies of hypnosis. (The section on hypnosis includes cases in which hypnosis alone has successfully anesthetized individuals undergoing major surgery. The biofeedback studies are significant primarily because they proved that processes previously believed to be autonomous could be brought under conscious control. This suggests that we might some day learn to direct our own immune and endocrine systems consciously.) Also included are well-documented individual cases involving saints, mystics, and even a few neurotics. Some involve Indian yogis who survived live burial for days on end. Others describe of the charisms, or the extraordinary events, surrounding the Catholic saints and mystics. Still others document phenomena as bizarre as false pregnancy in men. When compared to these kinds of phenomena, psychosomatic healing seems almost mundane.

II. Selection of the Evidence Presented

What we review here is evidence supporting a causal connection from thought to healing. The kind of causality we are discussing is "efficient" causality, i.e., the influence of an antecedent on a subsequent one.

One of the most common methods of finding a causal connection is by means of controlled statistical studies. These studies use probability theory to show that the correlation of an independent variable (or presumed cause) and the dependent variable (the effect) is stronger than it would be if the two variables were to occur at random. By itself, a statistical correlation does not identify a causal relationship. It only identifies a risk factor. To determine a causal relationship, a mechanism or formula explaining how the independent variable affects the dependent one is necessary. For example, two factors, male homosexuality and intravenous drug use, were both identified as risk factors for AIDS long before its cause, the human immunodeficiency virus or HIV, was found. The identification of the virus, as well as blood contact as the primary means of transmission, also explained the risk factors.

Risk factors do not always indicate causes. They may be merely other effects. As a hypothetical example, if cigarette smoking were found to be higher at lower socio-economic classes, and these same people also suffer from poorer nutrition, a statistical link between smoking and cancer would not demonstrate that smoking causes cancer at all. The real cause of the high cancer rate among smokers might be the poor nutrition suffered by the lower socio-economic classes, who also tend to be chain smokers. (There is the anecdote of the New Yorker who wore a lions-tooth necklace to protect himself from attack by lions. When his friend reminded him that one does not see many lions in the streets of Manhattan, he replied, "It works, doesn't it!") Serious researchers must exercise great care in eliminating extraneous variables from their studies, and how well they have done so is a major topic of debate in medical journals and academic journals in the social and biological sciences.

There are other ways to rule out random chance besides statistics. One of them is deductive logic. For example, if emotional depression adversely affects known immune system functions, and these functions protect us from disease, logic dictates that emotional depression also leads to disease. This relationship can be expressed in a syllogism:

Major premise: All immune system functions serve to protect us in some ways from disease.

Minor premise: Emotional depression adversely affects at least some of our immune system functions:

Conclusion: Therefore, emotional depression adversely affects some of the functions protecting us from disease.

Strictly speaking, more steps may be needed to construct a valid formal proof here in terms of quantifier logic, but the above syllogism should convince anyone who accepts the premises.

Another way to rule out random chance is common sense. For example, it is highly unlikely that the stigmata of Christ's wounds appearing every Good Friday on the hands of a devout Catholic would develop purely at random. That would be like a monkey pounding out the same Shakespeare sonnet on the typewriter week after week by randomly poking at the keys. Something else is at work here that certainly seems related to the individual's religious convictions. In any case, common sense would rule out a purely random connection.

In short the evidence from the placebo effect, psychoneuroimmunology, controlled studies, and certain kinds of historical and scientific evidence were chosen because they all indicate a genuine causal relationship going from thinking to healing. With that, we now turn to the evidence itself.

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Notes on Chapter 3

11 Bill Moyers, Healing and the Mind (New York: Doubleday, 1995), 94. The book is an edited transcription of a PBS miniseries by the same title recorded previously. Return to text