The second principle of Rationalist Medical Halacha is the Historical Corruption Principle. It is not uncommon that when a posek ignores this principle, that he may either ignore the fact that the halachic precedents were based on a different scientific understanding than his own, or worse, he may project his own understanding of science onto the earlier poskim and onto Chazal and assume that they meant something other than their true intention. Often it is the more scientifically inclined poskim who seem to make this particular blunder.
We mentioned in previous posts the two major current opinions, one held by the the brain death advocates, and the other by the cardiorespiratory death advocates. In the last post, we demonstrated how to apply the first Rationalist Principle to the primary Talmudic source for the cardiorespiratory death advocates.
Now I will focus my attention on the brain death advocates, and demonstrate the second principle of rationalist medical halacha at work.
The primary source for the brain death advocates is the Mishna in Oholot 1:6, which reads as follows:
A person does not impart impurity (the impurity imparted by a dead body) until his soul leaves him....If their heads are removed, even though there are movements - they are impure, similar to the tail of the lizard that it moves
The argument simply goes as follows: If the Mishna supports physical decapitation as death, even if there is still movement (and presumably this would be any movement - even heart motion) then clearly physiologic decapitation is also death halachically. Although this argument makes a lot of sense, I don't think this approach stands up well to the scrutiny of the Rationalist approach. In short, I don't think it is possible to claim that the gemara equates physical and physiologic decapitation. I still believe that the Chazal believed in cardiorespiratory death, as indicated in Yoma, but that they believed that physical decapitation should be considered death anyway, for other reasons which I will explain. In fact, the entire concept of physiolgic decapitation would have been so foreign to Chazal's understanding of anatomy and physiology that they probably would have thought that such a suggestion would be absurd. Let me explain why.
When the brain death advocates bring the Mishna in Oholot, they are forced to explain how they know for certain that physiologic brain death would be considered death according to chazal. It is well known that the chief proponent of the physiologic decapitation idea (PDI) is Rabbi Dr. Moshe Tendler Shlita. In an article published in 1990, Rabbi Tendler describes how he derives the PDI from this mishna. The Rambam explains the mishna in Oholot (why the movement of a lizard's tail is not real movement): "This occurs in some living animals because the source of motion does not spread to all its limbs from its' source and one place rather it is spread throughout the body". In Rabbi Tendler's words, the Rambam holds (and explains the Mishna this way) that there is a difference between organismic death and organ death i.e. although the organ may be "alive" the organism (the entire animal) may be dead. This happens when the movement is not directed by its source, which is of course, according to Rabbi Tendler, is the brain which controls movement.
Now this is a classic example of the Historical Corruption Principle in action. The Rambam did not believe that the brain was the source of motion! The Rambam (see Dr. Reichman's article, note 67). The Rambam believed that the source of motion was the heart! This can be found in numerous places in his medical writings, and in the Moreh 1:38,72. If you think this sounds strange, let us review for a moment a brief history of the ancient understanding of the function of the brain.
According to Aristotle, the function of the brain was to cool the innate heat of the heart. Thoughts, feelings, and decisions were all made in the heart. (see Aristotle, On Sleep and Sleeplessness, Part Three, trans. J. I. Beare. [Online here, scroll to second-to-last paragraph.]. Only after Aristotle did the Greek thinker Herophilus identify the brain as the source of intellect. It wasn't until the time of the Roman philosopher Galen (CE 129-199) that it was discovered that the brain wills and controls motion. The Rambam (see Max Meyerhoff "Maimonides Criticizes Galen Medical Leaves 3:1 1940) actually sided with Aristotle and believed that although the brain had a function in controlling movement, the actual origin of movement was the heart. So how strange indeed it is that Rabbi Tendler tried to use the Rambam's explanation of the Mishna in Oholot to prove that brain death is indeed death. According to the historical principle, we must understand the Rambam according to HIS OWN understanding of physiology, not by imposing modern ideas and imputing them to him. The Rambam clearly did not mean to explain the mishna that the reason why decapitation is death is because the central source of motion is dead if he didn't believe that the source of motion was the brain!
What then is the pshat in the Rambam? Why is physical decapitation considered death if the body is still moving? For that we need to understand the significance of the brain according to the Rambam. Although this is not the place for a detailed analysis of the Rambam's pshat in the Mishna, the bottom line is that the brain is an "eiver shehaneshama teluyah bo" and the Rambam goes out of his way to say that even if the head is attached by skin and soft tissue, but the spine is severed (like what would happen in a hanging) that the person is dead. If anything, this could prove that the Rambam would not hold of PDI, or he would have went even farther than that and said that even if it is totally attached, but not functioning, the person is dead, but if I said that, I may be guilty of violating the historical principle myself. If one looks carefully at Rabbi Kapakh's translation of the Rambam Peirush hamishnayot (my English translation of the Rambam Peirush on the mishna in oholot is based on the R' Kapakh version), one will see that the Rambam explained that in certain simple LIVE creatures, such as the Leta'ah (some sort of lizard presumably) the motion is not centrally directed, and thus there is a lot of movement even after the tail is severed. This movement proves that there is such a thing as movement that does not derive from the central life giving source i.e. the heart. In the same way, the mishna teaches us, that after death there could be movement that does not constituite life at all. That is all the rambam meant IMHO.
Let's look at one more area where the brain death advocates make the same blunder. In that same article, Rabbi Tendler brings another important source, the Shulchan Arukh, Yoreh Deah Chapter 370, based on a gemara in Chullin. The title of the chapter is "Who is considered dead even though he is alive". The Shulkhan Arukh (SA) lists two such people,one whose neck is broken, and the other who has a severe injury to his back which is split open. The SA explains that they are considered halachically dead, even though they may still be moving. However, a gosses (someone in the throes of death) is still considered alive, even with multiple wounds or a slit throat. Rabbi Tendler asks, "Why would the first cases be regarded unequivocally as instantaneous deaths, and the others not so regarded?" and he explains, "The answer is that such individuals experience a condition in which their blood pressure drops instantly due to a massive wound. Blood flow to the brain is interrupted, and they die because their brain dies within seconds or minutes of that interruption ..." So brain death is once again being injected into the SA, even though it is obvious that this was not the intent of the SA or the gemara upon which the SA was based.
It is important to mention that there is another group of authorities who advocate brain death as a possible criteria for halachic death, but from a completely different angle than the PDI of Rabbi Tendler and his supporters. This is most clearly articulated by Rabbi Dr. Avraham Steinberg in several articles. See this link here for one article easily accessible online. The bottom line of this opinion is that cardiorespiratoy death is the halachic definition of death as the gemara in yoma indicates. However, since the brain stem controls respiration, it should be obvious that if you can prove that the brain stem is totally dead, than by definition spontaneous respiration has ceased. In other words, brain death is only considered death because that causes breathing to stop.
This approach makes a lot of sense but it should be obvious that the gemara never intended to teach us that the death of the brain is the proximate cause of the cessation of respiration. However, at least it gets around the problem of the Historical Corruption Principle, as no claim is made that the gemara intended to teach us about concepts which would have been foreign to chazal. This is really another version of the opinion of the cardiorespiratory death advocates, with the understanding that the brain controls the action of breathing.
There is obviously much more to be said, but I think I would like to move on next time to the third principle and describe some of the strange and confusing consequences of trying to apply Halachic death criteria to modern medical situations. Looking forward to your comments.