About Intercessory Prayer: The Scientific Study of Miracles

Gil Gaudia, PhD


March 20, 2007


In 1748 the great Scottish philosopher, David Hume, first published his "lemon test" concerning miracles. It goes like this: "No testimony is sufficient to establish a miracle unless the testimony be of such a kind that its falsehood would be even more miraculous than the fact which it endeavors to establish. . . " Hume concludes his point by saying: "When anyone tells me that he saw a dead man restored to life, I immediately consider with myself, whether it be more probable that this person should either deceive or be deceived, or that the fact, which he relates, should really have happened. I weigh the one miracle against the other; and according to the superiority, which I discover, I pronounce my decision, and always reject the greater miracle. If the falsehood of his testimony would be more miraculous than the event which he relates; then, and not till then, can he pretend to command my belief or opinion."[1]

By carrying out research into the effects of "intercessory prayer" medical researchers are, in effect, attempting to study the existence of miracles, defined as an extraordinary event manifesting divine intervention in human affairs.[2]

Let me emphatically state at the outset, that I do not criticize anyone for praying for themselves or anyone else if they choose to. Nor do I deny that there may be benefits to some individuals that stem from prayer. These activities might stimulate subtle mechanisms of psychology and physiology which, when understood more fully, may add to the established benefits of medication and surgery, as they obviously do in psychiatric illnesses. Along with placebo effects, the alleged benefits of prayer may be the result of feelings of well-being, optimism and confidence that result from praying and similar practices like meditation or relaxation. I agree, all of this may exist, and could, perhaps should, be a subject of legitimate scientific inquiry.[3,4]

But the interaction of psychology and physiology is not the subject of my commentary. My comments are addressed only to what most people mean when they say, "I'll pray for you;" The meaning that implies a request for intercession from a "higher power." What this reference to prayer means, is that the wishes of the supplicants will be heard by some agent and if the agent is convinced to act -- the course of events will be changed for the better, in accordance with the prayer. Thus, the meaning of "intercessory prayer," which this commentary attempts to address is the study of the existence of miracles, which implies the study of the existence of God.

There is incredible irony in all of the previous "experiments" involving intercessory prayer. Every one of them has been seeking evidence of a most trivial kind that could even be mistaken for a placebo effect, or a statistical artifact, from an alleged Power of the most unimaginable magnitude. Power that presumably was the source of the astounding creation of hundreds of billions of galaxies, which are composed of hundreds of trillions of stars, dotted with singularities and "black holes" possessing immense gravity and crushing annihilatory densities; all of which are dancing with exquisite accuracy in spectacular elliptical orbits over a time- and distance-span of 14 billion light years; Power that has designed astonishingly complex molecular systems, composed of amazingly intricate atomic foundations; all operating according to the mechanics of gravity and other little-understood forces that bind atomic nuclei together while swarms of electrons maintain their balance around their stupendously dense centers in microscopic imitation of the grander galaxies; Power that orchestrated the rules of light propagation and spectrums of colors all arranged in fantastically diverse, visible, as well as invisible, wavelengths and patterns.

Meanwhile, experimenters seek evidence of this breathtaking immensity by searching for a barely measurable difference between the arterial blood flow of a few cardiovascular patients who were prayed for and a few other unfortunates who were not . . . a difference in blood pressure between 1 group of hypertensives who were prayed for and another group that was not prayed for. It is as if one were asking a composer with a quadrillion times the musical capacity and comprehension of a Ludwig Von Beethoven to demonstrate his musicianship by writing out the notes to "Three Blind Mice."

How petty and insulting to whatever deity these investigators claim to be investigating, when the most they can ask of that which has created biologic systems from algae to sequoia giganticus and amoebas to human brains "Let me see if you can fertilize this ovum in a Petri dish with one of your hands tied behind your back."

The issue is about prayer to a deity or his representative beings that do not exist within the known physical universe, a qualification acknowledged by most educated religious believers, which should include medical researchers who engage in the scientific investigation of natural phenomena. What I am trying to make clear is that those who believe in God and the power of intercessory prayer are speaking of concepts that are not material and therefore not part of the physical world. Yet they want to connect these phantasms with the scientifically demonstrated forces and structures of the physical world . . . and moreover, to have these influences measured in physical experiments.

Many of these studies claim to have demonstrated the effectiveness of intercessory prayer.[5] Of course, many do not, and one meta-analysis of 14 such studies concluded, "There is no scientifically discernable effect for Intercessory Prayer (IP) as assessed in controlled studies. Given that the IP literature lacks a theoretical or theological base and has failed to produce significant findings in controlled trials, we recommend that further resources not be allocated to this line of research."[6] I hasten to point out, that some studies indicate that there may also be certain disadvantages that accrue from similar psychological and physiological mechanisms. In a most notable example, in the April issue of the American Heart Journal, one of the study's findings was that "a significantly higher number of the patients who knew that they were being prayed for (59%) suffered complications, compared with 51% of those who were uncertain." One of the investigators, Dr. W. Bethea, said it is possible, "that being aware of the strangers' prayers also may have caused some of the patients a kind of performance anxiety. . . It may have made them uncertain, wondering am I so sick they had to call in their prayer team?"[7]

So not only do some "scientists" seem to believe that intercessory prayer can be helpful, they are also concerned that it could be harmful. This is suspicious, to say the least, because it should be apparent that, most of these "results," both positive and negative as well as neutral, are explainable either as psychosomatic effects, or even more likely, as statistical artifacts. But more importantly, if the concept of intercessory prayer has any meaning whatsoever, in the metaphysical sense, would that mean that the deity was not only ignoring the request, but in some instances, also punishing the supplicant as well?

Whatever the competing explanations may be, a major reason for the indeterminacy is that the dependent variables that are chosen in all of these studies, by their very nature, were not unambiguous enough to produce an unequivocal outcome. There is and always has been in these studies, the likelihood that the null hypothesis or alternative hypotheses prevail.

Finding differences between groups, especially differences brought about by a "treatment," is the sine qua non of experimentation. However, when 2 groups are compared on any criterion measure, there will always be some difference. The important task is to distinguish between a "measured difference," a "statistically significant difference," and an "actual or real difference." The first 2 are separate and unequal approximations of the third, which is unattainable reality, although the first 2 are often mistaken for the third. Neither of the first 2 can ever hope to be estimates of that which is outside of reality.[8]


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