“I put my heart and my soul into my work, and have lost my mind in the process” – Vincent Van Gogh

I shouldn’t have had that extra cheeseburger.

Theologians have been pondering over the nature of the human soul for a few millennia.  Only theologians have that kind of free time.  Nevertheless, many races, creeds, and colors throughout history have posited theories as to whether there is some enduring spiritual essence that persists after death, like cologne in a crowded elevator.  Answers are legion, but irrefutable evidence is sparse.  At the dawn of the 20th Century, no satisfactory consensus had been arrived at, but to our good fortune, we were beginning to find ourselves knee deep in scientists.  And scientists like themselves those big problems of cosmological significance.  In 1901, learned physician Duncan MacDougall (1866-1920) of Haverhill, Massachusetts hopped on the soul speculation bandwagon, and determined he would conduct experiments to answer a far more important question than the spiritual significance of the human soul.  He decided to find out how much the soul weighed.  His conclusion?  Three-fourths of an ounce (or it’s more infamous appellation – 21 grams).

There is a strong historical tradition of soul-weighing dating back to Ancient Egypt.  In the early Egyptian cosmology, upon death, people of sufficient pedigree were taken to the underworld of Duat, where their heart (representative of the soul) was weighed on a scale in comparison to an ostrich feather taken from the fashionable headgear of the goddess Ma’at.  If your heart was unburdened by a less than virtuous life, which in Ancient Egypt probably meant you didn’t actually beat your slaves to death, rather simply maimed them, it would weigh less than the feather and you would be escorted to the heavenly paradise of Sekhet-Aaru where you got to chill eternally with Osiris.  If your heart outweighed the feather, the goddess Ammit devoured it, and you were condemned to life in the underworld.  A lot of hearts being cannibalized by goddesses.  Reminds me of when I used to date.  Good times.

Well, the good Dr. MacDougall was not some weird cultist looking to revive the Egyptian pantheon.  He was a man of science.  I realize the distinction is a subtle one.  Now, it was 1901, and formalized institutional review boards to which one had to apply for human subject approval had yet to become a thing.  In fact, human subject approval probably consisted of your boss saying, “You’re right, that would be cool”.  MacDougall had the good fortune to be employed at a hospital in Haverhill where they just so happened to have a lot of terminal tuberculosis patients indolently lying about taking up valuable real estate while waiting for their expiration date.  To MacDougall this was an inexcusable waste of good resources for his research.  MacDougall concisely laid out the theoretical basis for his experimental design.

It is unthinkable that personality and consciousness continuing personal identity should exist, and have being, and yet not occupy space. It is impossible to represent in thought that which is not space occupying, as having personality, for that would be equivalent to thinking that nothing had become or was something, that emptiness had personality, that space itself was more than space, all of which are contradictions and absurd.  Since therefore it is necessary to the continuance of conscious life and personal identity after death, that they must have for a basis that which is space occupying or substance, the question arises, has this substance weight; is it ponderable? The essential thing is that there must be a substance as the basis of continuing personal identity and consciousness, for without space occupying substance, personality or a continuing conscious ego after bodily death is unthinkable. According to the latest conception of science, substance or space occupying material is divisible into that which is gravitative—solids, liquids, gases, all having weight—and the ether which is non-gravitative. It seemed impossible to me that the soul substance could consist of ether. If the conception is true that ether is continuous and not to be conceived of as existing or capable of existing in separate masses, we have here the most solid ground for believing that the soul substance we are seeking is not ether, because one of the very first attributes of personal identity is the quality or condition of separateness. Nothing is more borne in upon consciousness, than that the you in you, and the me in me, the ego, is detached and separate from all things else—the non-ego (MacDougall, 1907, p237-238).

We’re not so into the idea of luminiferous ether as the invisible substrate of the universe anymore, but otherwise MacDougall makes a somewhat logical, if bizarre case, and thus he set about some controlled tests to weigh the soul.  Qualifying as a subject in MacDougall’s experiment was not a simple matter of (a) dying soon, and (b) volunteering.  No, admissions criteria were stringent.  Subjects had to be aware enough to give consent, dying from a disease that causes great exhaustion (like tuberculosis) – the theory being that there would be negligible muscular movement upon death to unbalance the scales, and that their involvement would cause them no additional suffering.  The doctor tried to account for as many variables as he could, testing six total patients as they obligingly approached death.  MacDougall’s detailed description of the method used on his first participant was pretty much the model for all further tests.

The patient was under observation for three hours and forty minutes before death, lying on a bed arranged on a light frame work 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 an 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 bowels did not move, if they had moved the weight would still have remained upon the bed except for a slow loss by the evaporation of moisture depending of course, upon the fluidity of the faeces. The bladder evacuated one or two drachmes of urine. This remained upon the bed and could only have influenced the weight by slow gradual evaporation and therefore in no way could account for the sudden loss. There remained but one more channel of loss to explore, the expiration of all but the residual air in the lungs. Getting upon the bed myself, my colleague put the beam at actual balance. Inspiration and expiration of air as forcibly as possible by me had no effect upon the beam. My colleague got upon the bed and I placed the beam at balance. Forcible inspiration and expiration of air on his part had no effect. In this case we certainly have an inexplicable loss of weight of three-fourths of an ounce. Is it the soul substance? How else shall we explain it? (MacDougall, 1907, p240)

Five more patients were tested and to be fair MacDougall himself pointed out that the value of the data from two of his cases was dubious.  Apparently, in the case of a woman in a diabetic coma, there was interference from the family, and the final case died within five minutes of being placed on the scale, not giving them time to balance it properly.  Ultimately, MacDougall concluded (with an enormous number of caveats) that at the time of death the human body lost between half an ounce and one ounce that could not be accounted for.  To his credit, MacDougall repeatedly warned that his results were inconclusive and that further validation was required, but sadly the New York Times caught wind of his efforts and outed him, breathlessly reporting the discovery of the weight of the human soul.  MacDougall went on to perform a rather gruesome variation of the experiment on fifteen dogs, tranquilizing them, poisoning them, and then seeing if they lost any weight at the time of death.  They did not.  This made logical sense to everyone as according to the prevailing Christian philosophy among the experimenters, animals don’t have souls, a special dispensation accorded to only us egocentric little humans.

Modern scientists have been pointing out ever since MacDougall’s strange efforts that the experiment was flawed by its small sample size, the precision of the equipment, and lack of control over the conditions, not to mention the fact that nobody has ever been able to replicate the results.  No sense of poetry on these guys.  Personally, it seems far more comforting to me that when I die, rather than an express elevator to the Pearly Gates (wishful thinking on my part no doubt), twenty-one grams of me wanders off into the ether.  I hear the music is better there anyway, or as Lao Tzu said, “music in the soul can be heard by the universe”.  Maybe your soul is a 21 gram jam band.

MacDougall, Duncan.  “Hypothesis Concerning Soul Substance Together with Experimental Evidence of the Existence of Such Substance”. The Journal of the American Society for Psychical Research v1. New York: American Society for Psychical Research, 1907.
MacDougall, Duncan.  “Hypothesis Concerning Soul Substance Together with Experimental Evidence of the Existence of Such Substance”.  American Medicine v13. Philadelphia?: American-Medicine Pub. Co, 1907.