In hmolscience, Duncan MacDougall (c.1866-1920) was an American physician, one of the first experimental soul theorists, noted for his 1901 soul theory that if the soul exists it must have a mass that can be measured on a scale and be quantified scientifically.
Overview
In circa 1899, MacDougall expressed his soul theory views in a letter to a friend, as follows:
“If personal identity, and consciousness and all the attributes of mind and personality, continue to exist after the death of a body, it must exist as a space occupying body.”
In the years to follow, he then tested this theory by weighing dogs, horses, and people as they died, finding that on average that the soul weighs 3/4th of an ounce or about 21 grams. [1]
In 1901, MacDougall weighed six patients while they were in the process of dying from tuberculosis in an old age home. It was relatively easy to determine when death was only a few hours away, and at this point the entire bed was placed on an industrial sized scale which was reported to be sensitive to "two-tenths of an ounce". He took his results (a varying amount of unaccounted for mass loss in four of the six cases) to support his hypothesis that the 'soul' had mass, and when the 'soul' departed the body, so did this mass. The determination of the 'soul' weighing 21grams was based on the loss of mass in the first subject at the moment of death.
MacDougall later measured fifteen dogs in similar circumstances and reported the results as "uniformly negative," with no perceived change in mass. He took these results as confirmation that the 'soul' had weight, and that dogs did not have 'souls'.
This value then entered urban myth into the 20th century as the so-called "soul weight" of the average person; the 2003 film 21 Grams, starring Sean Penn and Benicio del Toro, being one example of this.
References
1. Fisher, Len. (2004). Weighing the Soul: the Evolution of Scientific Beliefs. London: Weidenfeld & Nicolson.
Further reading
● MacDougall, Duncan. (1907). “The Soul: Hypothesis Concerning the Soul Substance Together with Experimental Evidence of Such Substance”, American Medicine, New Series, 2:240-43.
External links
● Duncan MacDougall – Wikipedia.
