The article goes on to narrate a 1921 experiment perform by Duncan MacDougall, a physician, who claimed he was able to weigh a human soul. He accomplished this by measuring how much a person weighs before and immediately after death. After monitoring six deaths, he reported that people lost between 11 and 43 grams at death, which he attributed to the material weight of the soul. Others failed to replicate experiment, whereas other more prosaic explanations were proposed that accounted for the observation, such as water evaporation. One also wonders if six deaths was a large enough sample to reach such a conclusion, and question any hypothesis that conceived the soul as a material entity.
Please, recall our philosophical-theological definition of the spiritual, human "soul": as the ultimate internal principle by which we think, feel, and will, and by which our bodies are animated... capable of an existence separate from the body.. It is also immaterial and therefore the product of a special creative act, according to the 1909 Catholic Encyclopedia article. Whatever MacDougall was looking for was not what we Catholics understand as a "soul."
Bosveld continues her article describing other attempts to either directly detect the soul or explain its existence indirectly. Gerard Nahum falls into the first category, who wants to surround an expiring person with an array of highly sensitive electromagnetic sensors to pickup any type of "escaping energy." Nahum believes that "when a conscious entity dies, all of what's embodied in it cannot just simply disappear. It needs to either be transformed into something else within our space-time or it needs to transcend its existence here and move on to someplace else where it could potentially remain intact."
I don't wish to play the devil's advocate here and judge Dr. Nahum's research by only three lines of text, but I must approach his proposal with some skepticism. How does he know that "when a conscious entity dies, all of what's embodied in it cannot just simply disappear"? As a Christian, I know that's the case because faith supplements our reasoning from first principles. But, is that a notion we can prove and therefore defend empirically? And, why does this "escaping energy" be electromagnetic in nature? If it is, and it is transformed into "something else within our space-time" it would no longer be a "soul" as we Christians understand it and yet another apparent conflict between observed facts and revealed truths would ensue. Finally, if the "escaping energy" were to "transcend its existence here and move on to someplace else," then no scientific instrument would be able to detect the full transition, as any detectable trace of this "energy" would just "poof" out of existence in a manner indistinguishable from mere evaporation and in fact, it would be easier to explain that the escaping energy simply dissipated into oblivion, without recurring to transcendent explanations. Dr. Nahum's proposed experiment is, in my lay opinion, impractically fuzzy in its terminology and underlying assumptions.
The other set of indirect experiments include research into "near-death experiences" (NDE's) which include instances of "out of the body" consciousness by temporarily, clinically death persons. I want to gloss over this one not because the phenomenon isn't interesting in itself, but because this is a widely researched phenomenon and much has been written for or against the existence of an immaterial soul based solely on NDE's. I want to proceed to the one speculation which I find quite fascinating.
Anesthesiologist Stuart Hameroff and renowned physicist Roger Penrose are working on a model which explains consciousness ("the soul") as the result of quantum processes taking place in tiny brain cell structures called "microtubules." Hameroff says that under normal circumstances consciousness occurs at the level of space-time geometry in the brain, inside the microtubules. This is where the explanation gets a tad dicey, so this is a direct quote:
But the fluctuations extends down to the Planck scale [far smaller than an atom] because the microtubules are driven bioenergetically to be in a coherent state. When the blood supply and the oxygen stops, things go bad and the coherence stops, but quantum information at the Planck scale isn't lost. It may dissipate into the universe but remain somehow entangled in some kind of functional unit, maybe indefinitely. If the patient is revived, the information gets picked up again.Whoa, if I understand this correctly—and I am not claiming that I do—what Hameroff implies is that consciousness is an emerging property of complexly arranged matter and that it is a kind of matter itself, which is the same to say that it is energy (E=mc2, remember?) because at a Planck scale there is really no difference between matter an energy. These quantum interactions that form "consciousness" occur inside these microtubules.
According to Bosveld , Hameroff provided a mechanism to a theory of Penrose, in which the latter postulated the existence of a realm of "Platonic ideals" at the Planck scale which influences the workings of our minds. At these infinitesimal levels, these noncomputable "Platonic ideals" are embedded. These patterns were "recorded" at the time of the Big Bang which gave origin to our Universe, bridging, in the words of Italian astrophysicist Paola Zizzi, " the very early quantum computing universe and our mind."
Wow. This is all very impressive, but is it "true"? Although Hameroff shies away from the term "soul," is this "infinitesimal quantum information" the same as a "soul" as we Catholics understand it? Are these two terms describing qualitatively, even semantically, the same reality? We may argue in favor that both realities are equally "immaterial" for all practical purposes, because both are beyond the capabilities of any measuring instrument. Classical theologians and philosophers may object with reason that no matter how small something is, if is still part of this space-time, it remains a manifestation of matter-energy, however infinitesimally small. It's not a "soul" the way we understand it.
In my lay opinion, I don't think there has to be a fundamental disparity or opposition between the soul as Hameroff and Penrose postulate it and the way St. Thomas Aquinas explained it. Aquinas in his earthly existence could not conceive of quantum information at the Planck level, much less explain or fathom the behavior of matter-energy at that level. Aquinas, however, understood "beings" and he would've agreed that information quanta are beings, created beings belonging to the natural realm. The identity between Aquinas' concept of the soul and that of Hameroff/Penrose may be conceptually achieved if one equates infinitesimal quantum existence as Hameroff/Penrose explain it with incorporeality as Aquinas understood it. A soul is, they would agree, a kind of "subtle matter."
I think that many from the Christian standpoint tend to conceive the soul as a supernatural reality when in fact it isn't. The human soul belongs to the realm of nature and for that matter—no pun intended—so do angels. They all belong to the same continuum of natural, created beings. The only Being that is really supernatural, according to most theists, is God. He is the only one truly immaterial Being and infinitely beyond any thought, concept, and scientific measurability.
C.S. Lewis explored the concept of subtly corporeal "angels" in his Space Trilogy, which he termed "eldila." The eldila (singular eldil) are a species of intelligent extraterrestrial. The human characters in the trilogy encounter them on various planets, but the eldila themselves are native to interplanetary and interstellar space ("Deep Heaven"). In standard science-fiction terms, they are "multi-dimensional energy beings." They are barely visible as faint, shifting light. (Wikipedia). The notion, then, of subtly "material" spirits is not completely foreign to the minds of some orthodox Christian thinkers. Even for Aquinas, angels and the realm of the spirit, although appearing incorporeal to us, appear corporeal to God, (Summa Theologica: Question 50, Article 1, Reply to Objection 1) although he made clear that angels appeared "corporeal to God" not as if "anything incorporeal existed in them," at least from our perspective. This is another way of saying that for God, everything created is "matter" even beings we would term "spirit."
Again, for the Hameroff/Penrose "soul" hypothesis to agree with the Catholic concept of a spiritual "soul" an understanding must be reached equating quantum "infinitesimality" with Aquinas' "incorporeality." This, I am not prepared to do, because I am neither a physicist, nor a fundamental theologian, nor a metaphysician, nor a linguist. In order to answer that question in the affirmative, in order to assert that equivalence, one would need to formulate a common theological and empirical understanding of consciousness across several scientific, philosophical, and theological disciplines to create a unified framework in which everyone agrees that they are seeing the same fundamental reality from different theoretical vantage points. I am not that smart to formulate the "Grand Unification" theory needed to explain the equivalnce. I can only limit myself to state that, intuitively, as I see it, no fundamental contradiction exists between both understandings of the concept of a spiritual "soul."
The existence of "Platonic Ideals" at the Planck level, as proposed by Penrose, is also fascinating and rich in possibilities. "Platonic Ideals" only exist in God's mind, according to classical theology. If these exist in the Universe since the Big Bang, it begs the question as to Who placed them there for other minds to find and for the Universe to develop as a consequence of coherent and interdependent natural laws. Once Plato makes it into the mix, God is not really far behind. We only need a new St. Augustine or Aquinas, with a little bit of Penrose and Hameroff, to place Him there.
As for the question, "how much does a soul weigh" the answer is true both in the Hameroff/Penrose hypothesis as well as in Aquinas': nothing, because neither quantum infinitesimality— Hameroff/Penrose would say— nor incorporeality, as Aquinas would have it, can be weighed. As far as they are all concerned, the phenomenon is "immaterial" and so is the answer. ;-)