society will agree that some capacity to think, to perceive, to respond and to regulate and integrate bodily functions is essential to human nature. Thus, if none of these brain functions are present nor will they ever return, it is no longer appropriate to consider a person as a whole as being alive.’
Expressions of this sort are rarely, if ever, found in halakhic literature, where human life or death are empirical issues.
DECAPITATION
There is an additional halakhic explanation of brain death other than that of the cessation of respiration.
In the Mishnah '’, we learn that if the head of an animal is cut off, it becomes unclean,(as a dead creature), even if its limbs continue to quiver, just like the lizard whose tail still twitches(after it is cut off).
Dr. Moshe Tendler , son-in-law of Rabbi Moshe Feinstein , explains that the authorities of Jewish Law considered the decapitated individual dead immediately upon severance of the spinal cord although cardiac function had not ceased. The residual life is considered to be without ethical import"like the twitching of a lizard’s amputated tail." (M. Ohalot 1.6) It would follow logically that irreversible loss of spontaneous respiration due to interruption of blood flow to the brain stem is tantamount to a physiologic decapitation.’
IS ORGAN TRANSPLANTING HALAKHICALLY PERMISSIBLE?
What is the halakhic and practical significance of brain death today? Of all of the areas of Jewish medical ethics, perhaps its definition is most crucial for organ transplanting.
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