Yale clinical neurologist Dr. Steven Novella posted recently about Dr. Richard Gallagher, a well-credentialed psychiatrist trained at Yale who provides psychiatric consultation services to the Catholic Church. Dr. Gallagher does so in situations in which demonic possession is considered a possibility and exorcism may be an option. The Church uses exorcism when demonic possession is clearly shown to be present, but generally Church officials involve psychiatrists and other medical experts to rule out psychiatric diseases as the cause of the symptoms before an exorcism is undertaken.

Dr. Gallagher is convinced that demonic possession is real, and he has had extensive professional experience with these patients. He describes witnessing such hallmarks of possession as revelation of hidden knowledge by the patient, superhuman strength, sudden movements of inanimate objects, etc.

Novella, who was interviewed (as a “skeptic”) for an article about Gallagher’s work, describes Gallagher as a “sensational crank”:

Gallagher’s evidence that some people are actually possessed is predictably thin and proves only his lack of critical thinking. He cites the claim that possessed people display hidden knowledge, but his examples are far more easily explained as cold reading. He cites displays of extraordinary strength, which is not unusual for ordinary people under the influence of adrenaline.

He also cites hearsay – other people have told him they saw levitation, although he never witnessed it himself….

I have already addressed the “secret knowledge.” The other evidence often offered is essentially that weird stuff happened. It’s not hard to have thing fall of shelves, or even fly across the room. You can just throw it. Did Julia throw the book when no one was watching? Did she have an accomplice? Did a book just fall off the shelf because of other commotion in the room? I don’t know, because we are not provided actual evidence to investigate, only word of mouth….

The format that [the journalist] follows is this: First, setup the premise, a self-described “man of science,” a Yale-trained psychiatrist who has become convinced by compelling cases that demonic possession is real. Let the sensational crank lay out their story in the beginning of the article, to control the framing, and to paint themselves as a hero.

Then, deeper into the article than most people will read, include the token skepticism. Yeah, but this skeptic thinks that Gallagher is wrong and here’s why. Granted, that’s better than no skepticism, but not much.

Because the token skepticism is then followed by giving the crank the final word – they get to answer the skeptics, but the skeptic has no opportunity to respond further.

Why, exactly, would Novella discount the professional experience of another physician, who has considerable expertise in a field in which Novella has none? After all, Gallagher has examined the patients and considered the evidence first-hand. Novella has not. Is Dr. Novella aware of any aspect of Gallagher’s work or personal life that would lead one to think that Gallagher is a fool or a liar? Why would Novella dismiss Gallagher’s work out of hand, based on no evidence and without any professional knowledge of the patients involved?

So let’s take a look at Novella’s claim that demonic possession is sensationalist nonsense. My purpose here is not to prove or discount demonic possession per se. My purpose is to examine the rational and scientific basis for belief in, or denial of, demonic possession. I will approach the metaphysical and scientific questions from the perspective of the Catholic Church, which has a well-organized and careful approach to discernment of demonic possession and to the theological and philosophical underpinnings of the existence of demons.

In the Catholic understanding, demons (and angels) are separated intelligences. God’s creation is, to use a Scholastic term, a Great Chain of Being. At the lowest end of the Chain of Being is prime matter, which is pure potency and does not have existence of its own. At the highest level of Being is God Himself, who is pure Spirit and whose essence is existence itself.

Just above prime matter are simple inanimate substances, like the elements, composed of identical atoms. Next are compound inanimate substances, such as molecules and other inorganic matter. Next are plants, that have vegetative souls that provide nutrition, growth, metabolism, and reproduction. Next are animals, who in addition to vegetative functions have locomotion and sensation, perception, appetite, and memory.

Straddling the material and spiritual realms are human beings, who have souls with vegetative and sensitive powers and immaterial intellectual (spiritual) powers as well.

Between humans and God, in the Chain of Being, there is a space for what the Church calls “separated intelligences.” These are essentially intellects and wills without material bodies. These (hypothetical) beings are what we call angels and demons. They are pure forms, without composition with matter.

The logical and metaphysical underpinnings of the existence of angels and demons was worked out in exhaustive detail by St. Thomas Aquinas in the 13th century — he is, in recognition of his investigation of the philosophical implications of the existence of separated intelligences, called the “Angelic Doctor.”

It is important to understand what is meant by separated intelligences. Note that the Church does not teach that demons are little red creatures with horns and pointy tails, nor does she teach that angels have wings and harps. Popular representation of such beings through the ages is artistic and has nothing to do with actual theology or metaphysics. In the Church’s teaching, demons have no bodies — they are pure intellects, without matter.

Now, one can ask: Why posit that separated intelligences exist? What is the evidence for them? Let’s consider three lines of evidence:

1. Scientific evidence: There has never, to my knowledge, been a scientific experiment that systematically examined the question of demonic existence or non-existence. As separated intelligences, demons wouldn’t be visible in the ordinary way science explores the natural world. So we would have to look for their effects in nature. Science has not done that, in any systematic way. So science, if it is to be honest, must remain silent on the question of demonic possession.
2. Anecdotal evidence: There is undeniably massive anecdotal evidence for the existence of demons and angels. Massive. Millions of people for thousands of years have had experiences with what they believe are separated intelligences, of benevolent and malevolent variety. Many of these people (e.g., Dr. Gallagher but including countless priests and laypeople) are highly educated and perfectly rational witnesses. To deny any reality to their experiences is a very radical denial. Such denial should presumably be based on substantial evidence that they are fools or liars. No such evidence is forthcoming.
3. Logical evidence: There is a Scholastic maxim that “The perfection of the cause is reflected in the perfection of the effect.” “Perfection,” in scholastic terminology, refers to actuality, to the extent to which a thing manifests itself fully. One of the logical reasons for believing in separated intelligences is that because God is perfect (fully actual), His creation will manifest perfection as well, in the sense of a full actual range of creatures. He would not leave gaps in His Chain of Being. This is the logical Scholastic argument for the existence of separated intelligences: They complete the Great Chain of Being, and their non-existence would be inconsistent with God’s perfection. Before you dismiss this line of reasoning, keep in mind that it is used regularly in natural science. The most dramatic example is Paul Dirac’s prediction of the existence of anti-matter (positrons) based on solutions to equations in quantum mechanics. He saw that the equations worked for electrons with positive as well as negative charge, and he predicted their existence based on his inference to completeness of nature inherent to his equations. Shortly thereafter, positrons were empirically discovered. Such predictions based on the “perfection” of nature are routine in science. Black holes, the Big Bang, and gravity waves were all predicted (before there was empirical evidence of their existence) by extrapolating from equations and presuming the “perfection” — the full actuality — of nature. This is the same reasoning Scholastic philosophers used to infer the existence of separated intelligences.

So, with all of these lines of evidence taken into account, do demons exist, and is demonic possession real? I don’t know, in the sense that I have neither scientific evidence (one way or the other) nor personal experience of their existence. Neither does Dr. Novella. I do believe demons exist, mainly because of my Catholic faith, but also because of the massive anecdotal evidence for their existence (countless millions of people have encountered them) and because of the logical metaphysical arguments for their existence, which I find quite reasonable.

I should also note that I have two friends who have had experiences they believe are demonic/angelic. One friend had an infestation of poltergeist in his home. Bits of metal — pieces of iron and screws and bolts — kept dropping in his living room out of thin air, and they would shoot across the floor in front of him. He searched and found no source for the objects and no explanation for these bizarre phenomena. Finally, after several months, he called a priest (this was in my diocese), who investigated and witnessed and corroborated the events. The priest consulted an exorcist. An exorcism was performed and the phenomena stopped. My friend is a perfectly rational medical professional, and he is as astonished and perplexed by these phenomena as one might expect. He told me that he wouldn’t have believed it if he hadn’t seen all of this himself.

I have another friend who is a medical professional (and who is not particularly religious) who had an encounter that she believes was with an angel. I won’t go into the specifics, but the encounter occurred at a crisis in her life and radically changed her professional aspirations. The encounter, if she is relating it as it happened (and I believe her), is impossible to explain as an ordinary encounter with a human being, because it involved a physical impossibility in the encounter. Her story is remarkable and quite compelling. And she is a modest, rational, and eminently sane woman who I have known and worked with closely for a decade. She is not lying.

There are strong anecdotal and logical reasons to believe that separated intelligences — angels and demons — exist. I wouldn’t say that they rise to the level of scientific “proof,” but the evidence is very strong, and most important things we believe every day aren’t “proven” scientifically. Very little of what we know to be true in our everyday life is “scientifically proven.”

Dr. Novella clearly believes demons don’t exist, but I point out that he has no scientific basis or even a logical basis for making that claim. It’s quite clear that he doesn’t even know what demons are, in the scholastic sense, and knows (or cares) little about the genuine evidence in metaphysics and countless personal experiences for their existence. He merely disbelieves in demons because he’s a materialist, and demons are not critters in the materialist menagerie.

Dr. Novella has an ideological bias against the existence of separated intelligences. And that’s OK — we all have our biases. We all see the world through the prism of our own presuppositions and beliefs. I do so no less than Dr. Novella does so. But it is incumbent on an honest self-aware interlocutor to admit bias. Dr. Novella poses as an unbiased “skeptic,” in quest of truth without bias. He is not.

The one argument Dr. Novella uses to deny the existence of demons that should be taken seriously is the apparent lack of video documentation of superhuman acts — superhuman strength, levitation, etc., that might be expected if demonic possession were real. It’s a fair point. The answer to that objection is that separated intelligences are intelligences, and as such they have motives and purposes. As intelligences, they manifest themselves differently than inanimate objects would be manifest. They are not necessarily compliant with microscopes and video recorders. Exorcists and others who deal with these intelligences believe that they don’t want their existence to be demonstrated irrefutably. Demons, in this view, prefer to do their work in the shadows.

Now, this may seem to be a case of special pleading, but if so, it must be applied broadly to human affairs, not merely to the question of demonic possession. Does embezzlement occur, despite the lack of YouTube videos of embezzlers at work? Does rape occur, despite the lack of video documentation of rapes? Intelligent agents often conceal their work, especially if their work is malevolent and concealment furthers their aims. In order to prove the existence of embezzlers and rapists, we look to their effects, both to the witnesses of their effects and to the circumstantial evidence they leave behind. There is no reason to insist that separated intelligences do not conceal themselves as well, and we are justified in looking for evidence of their existence in witnesses and circumstantial evidence. Such evidence for the existence of demons, like the evidence for embezzlers and rapists, is very strong. Embezzlement and rape can be demonstrated “beyond a reasonable doubt” without YouTube videos. Why not hold demonic possession to the same standard?

So this is the evidence for demonic possession: the personal experience of millions of people, including the experience of highly educated professionals (priests, philosophers, scientists, and physicians among them), a massive trail of circumstantial evidence, and a logical argument (of a sort widely used in science) that separated intelligences are necessary to fill a space in the Great Chain of Being.

About this quite strong evidence, materialists are adamantly skeptical. So let’s look at the evidence that materialists (such as Dr. Novella) accept for their own beliefs.

Millions of materialists believe that our universe came from nothing for no reason, that essentially infinite numbers of universes are actualized continuously by quantum processes, that upwards of twenty or so invisible spatial dimensions are rolled up in infinitesimal vibrating strings that form the fabric of the cosmos, that cats can be simultaneously dead and alive, and that any moment now we will be saved or damned by benevolent or malicious space aliens (benevolent and malicious aliens are, of course, merely the angels and demons of materialism — except that, unlike separated intelligences, there’s no evidence for aliens whatsoever).

Even more bizarre is the belief by materialists that life itself — the genetic code, the intricate nanotechnology in cells, and the elegant physiology of complex organisms — evolved by natural selection, without any intelligent agency. I point out that there is immeasurably more evidence for separated intelligences than there is for the origin of species by random mutation and natural selection, which has never been videotaped, or seen, by anyone.

What is the evidence for these materialist fables — multiverses and aliens and live-dead cats? There is not a single witness, nothing but presuppositions and highly circumstantial evidence at best. These materialist fables are a lot crazier than witnesses’ reports of experiences with separated intelligences.

That said, some of the materialist fables may be true (perhaps there is a multiverse; perhaps there are extra dimensions rolled up in cosmic strings; perhaps organisms can exist neither dead nor alive in quantum superposition). Perhaps separated intelligences exist. The science is still out on all of these questions, and the lack of scientifically reproducible data is more of a problem for multiverses than it is for demons.  At least it may be said that separated intelligences, in addition to their theoretical plausibility, have millions of witnesses, including many respected professionals like Dr. Gallagher and my two friends. How many people have witnessed multiverses, live-dead cats, or speciation by natural selection?

Contra Dr. Novella, who swallows materialist dogma by the gulp, there is no scientific basis for categorically denying the existence of demons. Such denial is merely ideological prejudice, not reason or science or “skepticism” of any respectable sort.

Image credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA)-ESA/Hubble Collaboration [Public domain], via Wikimedia Commons.