The human soul is at the centre of most religions and, depending on the context, can be viewed as dogma—in other words, an indisputable issue that doesn’t need to be proven to exist. But could modern science identify, size and weigh the soul?
Science and faith do not necessarily need to walk together, but, at times, scientists can respond to phenomena or beliefs based on scientific experiments. In this case, which involves measuring the human soul, the American doctor Duncan MacDougal is one of the few known to pose this challenge.
MacDougal’s conclusion, reached more than 100 years ago, is that the human soul exists and that it would weigh 21 grams, but the evidence obtained from his experiment is questionable and controversial, according to experts. Furthermore, no other researchers have confirmed his findings.
Trying to weigh the human soul
“The essential thing is that there must be a substance as the basis for the continuity of identity and personal consciousness, for without a substance occupying the space, a personality or a continuous conscious ego after bodily death is unthinkable”, says MacDougal, in the year of 1903, in a study published in the scientific journal of the American Medicine Association.
Seeking to prove the existence of this substance, the American doctor proposed a series of experiments to verify the weight of the human soul. Tests were carried out on six people, who were dying. The causes were varied, such as tuberculosis and complications from diabetes.
When vital signs were significantly weakened and death was most likely approaching, patient beds were transferred to industrial-sized scales. There, the measurement would take place. Despite the six participants, the weight of 21.3 grams was confirmed in only one of the cases, which reinforces the limitations of this research.
Asked about the validity of the test by Popular Mechanics magazine, AMDA researcher and institutional research director Donald Everhart pointed to the fact that the sample of the soul experiment was too small to be reliable. Another issue to consider is the accuracy of the scales used.
Phenomena that can change body mass?
“I am aware that a large number of experiments would have to be done before the matter could be proved, beyond any possibility of error”, states doctor MacDougall himself about the limits of his research. At this point, it is still necessary to prove that the loss of mass is not related to any other physiological process that occurs after death.
After all, after the last breath, the body goes into an immediate process of decline. For example, the muscles relax and release some unwanted substances such as faeces and urine. The corpse tends to perspire, sweat is eliminated, and the lung is emptied. Gases are also released by the body. At this point, different variants may have affected MacDougall’s experiment, which makes soul weight—if it exists—a big mystery.