Dr. Duncan MacDougall, a physician of Haverhill, Massachusetts, became obsessed with the question of the substantiality of the human soul. In 1907, he performed several experiments of such a bizarre nature that they would never be allowed under today’s medical protocols. He tried to weigh the human soul! In retrospect, he was in search of the mystery of life. As we shall see, he was asking the wrong question.

Let’s take a look at what the world was like during his era, almost a hundred years ago. This was the era of spiritualism, where theosophy (an earlier manifestation of the New Age movement) had become quite the rage of Europe and America. It raised many philosophical questions about the spiritual nature of man. The rise of public consciousness to the possibility that the human soul had some sort of substance could be seen in the back rooms of the séance chambers, as the participants await the spirit that might emerge when summoned.

During this period, spirit photography was a burgeoning enterprise. Large and clumsy glass-plate cameras were set up on heavy tripods, awaiting confirmation from the medium that a spirit was present. Lens shutters were clanked open, while all that were present held their breaths. At the proper moment, the photographer would spark his flash powder, creating a brilliant explosion and cloud of smoke.

Observers often reported that in the after-image of the flash, they would see a materialization of one kind or another. Some folks reported to see a vaguely human shape and others a disembodied hand, or ace would appear and be seen.

The spiritual theatrics stimulated the thought that, after death, the human soul persisted in some detectable form. Spirit mediums liked to call it “ectoplasm,” the stuff from which the soul is fashioned. Sometimes this material was observed to pour from the mouth, nose, and ears of the trance medium, only to vanish when the lights in the room were turned on. This was an attempt to prove that the human soul was formed from a material substance that was invisible under ordinary circumstances. The human soul was thought to have mass, like ordinary human flesh, only much lighter and less substantial. The popular theory grew, that the soul might soon be detectable, using the instruments of “modern science.”


The early 1900’s was a time when doctors were the authoritarian figures in white smocks. It was a time when scientific experimentation of all sorts was unrestricted and many false deductions from this period are seen in the records of many physicians who experimented with “phrenology,” the study of the size and shape of the cranium, better known as the skull, especially the part enclosing the brain.

This brings us back to the activities of Dr. MacDougall. For whatever reason, he was convinced that the human soul consisted of a substance that could be affected by gravity. He thought that it had weight. And he was not the first. In his own memoirs, MacDougall recalled that Rudolph Wagner, a physiologist at the Gottingen Congress of Physiologists, had suggested to his fellows that there was something called a “special soul substance.” In the year 1854, Wagner had challenged his colleagues to find it, but in the years following, no one had ever confronted his dare with experimentation.



That is, until MacDougall’s famous 1907 experiment. His apparatus was simple, yet required a rather exacting calibration. He built a lightweight frame upon which the entire weight of the bed was borne.

Thus, the bed and the platform upon which it was suspended were carefully poised against a beam-balance scale. When a patient was placed upon the bed, the calibrated beam could be set at zero. Then, if the patient’s weight changed in the slightest, the beam could be rebalanced and the difference noted. Dr. MacDougall’s experiment was thus set and ready. He began to test a number of dying patients to see whether he could note any change in their weight at the moment of their passing. He tested six subjects in all, with varying results.

In his own words, from the 1907 edition of American Medicine, “My first subject was a man dying of tuberculosis. It seemed to me best to select a patient dying with a disease that produces great exhaustion, the death occurring with little or no muscular movement, because in such a case the beam could be kept more perfectly at balance and any loss occurring readily noted.

“The patient was under observation for three hours and forty minutes before death, lying on a bed arranged on a light framework built upon very delicately balanced platform beam scales.

“The patient’s comfort was looked after in every way, although he was practically moribund when placed upon the bed. He lost weight slowly at the rate of one ounce per hour due to evaporation of moisture in respiration and evaporation of sweat.

     “During all three hours and forty minutes I kept the beam end slightly above balance near the upper limiting bar in order to make the test more decisive if it should come.

     “At the end of three hours and forty minutes he expired and suddenly coincident with death the beam end dropped with audible stroke hitting against the lower limiting bar and remaining there with no rebound. The loss was ascertained to be three-fourths of an ounce.

     “This loss of weight could not be due to evaporation of respiratory moisture and sweat, because that had already been determined to go on, in his case, at the rate of one sixtieth of an ounce per minute, whereas this loss was sudden and large, three-fourths of an ounce in a few seconds.”

The doctor noted that any bodily fluids lost at death were retained on the bed. They would thus, continue to be weighed. Furthermore, he and an assistant tested the effect of residual air, exhaled from the lungs at the time of death. They took turns lying upon the bed, inhaling and exhaling as hard as possible. With the beam balanced, they were unable to detect any variation at all.

After checking any possible explanation for the weight loss, he wrote, “In this case we certainly have an inexplicable loss of weight of three-fourths of an ounce. Is it the soul substance? How other shall we explain it?”

In modern scientific measure, MacDougall discovered that the body instantly lost 21.262 grams at the moment his patient died. This is not an insignificant weight. Hold five quarters in your hand, and you can feel for yourself that this is a significant mass.

At this point, the doctor must have been quite excited. His first patient, and already, he had achieved a measurable result.


The second subject, a man in the final states of tuberculosis lay on the balanced bed for four and ½ hours. During this time, the patient steadily lost weight at the rate of about three-quarters ounce per hour. At heart stoppage, the patient suddenly lost half an ounce, which was measured about fifteen minutes later at a little over an ounce and a half.

MacDougall’s third case, also a terminal case of tuberculosis, showed a weight loss of one and a half ounces, plus an additional ounce a short time later. The fifth case showed a small drop of about three-eights of an ounce at the instant of death, but seemed to the doctor less convincing than the previous examples.

The sixth and final death occurred so quickly after the patient was placed upon the bed that no measurement could be taken.

Did he prove that the soul has substance? Certainly not. But he, himself, was convinced.

Later, he set up a new experiment, in which he observed the final moments of fifteen dying dogs, anesthetized so that they would lie still. In each of these cases, he reported that there was no weight change at the moment of their deaths.

From this, he expressed his belief that dogs don’t possess souls, as do humans. He seemed to be addressing theology in the only way that made sense to him, through “science.”

Does a soul have substance? If so, it may reveal that just as science affirms, energy can be changed from one form to another form, but can’t be created or destroyed. At death, the soul may flow from the body as it changes from one form to another.

Speaking in spiritual terms, the mystery of life is reserved to the Almighty God. Dr. MacDougall may have thought he could attain some clue that would establish the living soul as a physical reality. But, in fact, his pursuit was in vain. Life comes from God alone. Even if it can be observed as in Dr. MacDougall’s experiments, it cannot be explained in human terms.

The Biblical Soul

In the Bible, the first mention of the soul is in Genesis 2:7, where it is recorded that the first man was formed of earthly material. Life was then breathed into his nostrils and he “became a living soul:”
“And the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.”

This brief description of man’s creation raised far more questions than it answers. First, what is “life?” Until this mysterious ingredient was added to him, man was just a physical construction. But when life was added, he became a living soul, in the Hebrew, a neshamah. This term expresses the higher soul, the vital spirit, linked to the Creator. In both classical and modern Hebrew, it expresses the idea of respiration and vitality.

We can look at a living thing and describe it as “living.” But we can’t say what “life” is. For centuries, men have speculated about the “life force.” An attempt to measure it is what ultimately drove Dr. MacDougall to perform his curious experiments.

On the human plane, there will always be the question about how the energy of life is encapsulated in flesh during the life span of a man, then released to return to the God who breathed it, while apparently retaining its form, experience, memories and identity.

The old Testament regards the soul as one’s core being, the part of the man that survives death and goes on to judgment or reward…either separation from God or eternal fellowship with him. All the commands of the Lord are incorporated into the “Shema,” the command for Israel to hear and obey:

     “Hear, O Israel: The LORD our God is one LORD:

     “And thou shalt love the LORD thy God with all thine heart, and with all thy soul, and with all thy might.

     “And these words, which I command thee this day, shall be in thine heart”
(Deuteronomy 6:4-6).

These words, treasured by every Jew, are an exhortation to respond to his Lord with love. For it was, after all, the love of God that breathed life into Adam in the first place. The Bible uses the heart to depict one’s drive, desire and motivation.

These words ask that one channel the desires of his soul and the force of his strength into the love of God. It is not a legal conscription, but a passion of the heart. Or, as we say in the modern world, one should have a devotion to the Lord, “heart and soul.”


The ages-long view is that the soul was damaged, unable to reach Heaven without a Redeemer. However, in the New Testament we are told: “And you hath he quickened, who were dead in trespasses and sins” (Ephesians 2:1). Man was originally designed to be a creature of spirit, in continual fellowship with God. The risen Christ has “quickened” us…returned to us that same mysterious life-force that was breathed into the nostrils of Adam. He was spiritually linked to God…until he disobeyed.

Note, in the following words of First Corinthians, that for the redeemed, the “living soul” will one day be transformed from a natural body – with a soul – into a spiritual body. The soul, then, awaits transformation:

     “So also is the resurrection of the dead. It is sown in corruption; it is raised in incorruption:

     “It is sown in dishonor; it is raised in glory: it is sown in weakness; it is raised in power:

     “It is sown a natural body; it is raised a spiritual body. There is a natural body, and there is a spiritual body.

     “And so it is written, The first man Adam was made a living soul; the last Adam was made a quickening spirit.

     “Howbeit that was not first which is spiritual, but that which is natural; and afterward that which is spiritual.

     “The first man is of the earth, earthy: the second man is the Lord from heaven”
(I Corinthians 15:42-47).

We, the faithful in Christ already posses that Spirit. It strives with our spirit, as we await the resurrection. As the Apostle Paul put it:

 “And the very God of peace sanctify you wholly; and I pray God your whole spirit and soul and body be preserved blameless unto the coming of our Lord Jesus Christ” (I Thessalonians 5:23).

Humans are intended by God to be spirit-creatures. Those like Dr. MacDougall, who attempt to discover truth by studying the human soul, will always be asking the wrong questions. Instead of attempting to learn the truth of the soul and the wisdom of the earth, they should seek the Truth of the Spirit. It cannot be weighed, except in the balances of the Creator.