The very question of the existence of the soul, of course, is anti-scientific, but there are legends that the soul weighs 21 grams. Where does this figure come from?
The existence of the soul is a powerful concept that is a central part of many religions, comforting in the face of death. Perhaps that is why some were dissatisfied with the fact that the questions of the soul did not leave faith, and turned their attention to science to prove that the soul exists. If you’ve ever heard that the soul weighs 21 grams, or seen the 2003 movie “21 grams” hinting at this fact, you’ve heard about the results of one of these rather unusual experiments.
So how much does the soul actually weigh? Well, the bad news is that, of course, no one can say that. Science cannot prove that the soul exists, and scientists cannot weigh it. But the strange story of one doctor’s attempt to weigh the soul is worth listening to.
How the doctor decided to weigh the soul
The story begins at the turn of the last century in Dorchester, a neighborhood of Boston. A respected doctor named Duncan McDougall had a research idea: if people have souls, he thought, these souls should take up space. And if souls take up space, then they must have weight, right?
There was only one way to find out, MacDougall reasoned. “Because … the substance considered in our hypothesis is organically connected with the body before death, it seems to me more reasonable to think that it should be some form of gravitational matter, and, therefore, it can be detected at death by weighing a person at the time of death,” he wrote in a scientific article that eventually he will publish it in 1907.
McDougall teamed up with the Dorchester Home for the Consumptive – in fact, a hospice for patients with late-stage tuberculosis, because at that time this disease was considered incurable. McDougall built a large scale capable of accommodating a bed and a dying tuberculosis patient. McDougall explained in his article that tuberculosis was a convenient disease for this experiment because patients died in “great exhaustion” and without any movements that could shake his scales.
McDougall’s first male patient died on April 10, 1901 and the doctor noticed a sudden drop in his weight by 21.2 grams. And at that moment, a legend was born. It didn’t really matter that McDougall’s next patient lost 14 grams 15 minutes after he stopped breathing, or that his third case showed an unexplained two-step loss of 14 grams, followed by another 28.3 grams a minute later.
McDougall ruled out case 4, a woman dying of diabetes, because the scales were poorly calibrated, in part due to “significant interference from people opposed to our work,” which raises several questions that McDougall did not seem keen to answer in his report. Patient 5 lost 10.6 grams of weight, but subsequently the scales failed, which also caused doubts about this figure. Case 6 was ruled out because the patient died while McDougall was still adjusting his scales.
McDougall’s study had a tiny sample size and its results were everywhere, but even at the time it raised serious doubts that weight loss refers to the mass of the soul. To McDougall’s credit, he acknowledged that additional measurements are needed to confirm that the soul has weight. This did not happen — partly for ethical reasons, and partly because his experiments were few… strange. According to Mary Roach’s book “The Ghost: Science Solves the Afterlife” (W. W. Norton & Co., 2005), a rancher in In early 2000, Oregon tried to repeat the soul-weighing experiment with a dozen sheep. Most of them gained from 30 to 200 grams after death, although the gain lasted only a few seconds before the sheep returned to their original weight.
All this shows that science does not even remotely know the weight of the soul and whether the soul exists at all. Most likely, this question will be left to religion.