Tracking Baruch Brody’s view, brain-life theorists claim that in order to be fully human, a being must possess properties “such that their loss would mean the going out of existence (the death) of a human being” (Brody 1975, 102). The property of being human, they argue, is human brain function. J. Savulescu, for example, contended:
If we cease to exist when our brain dies, we only begin to exist when our brains start to function. Consciousness does not begin until after 20 weeks’ gestation. Thus we do not begin to exist as persons, as morally relevant entities, until at least 20 weeks of fetal gestation. The question of when and if killing occurs does not even arise until at least 20 weeks’ gestation. (Savulescu 2002, 134).Brain-life theorist John M. Goldenring¹ concisely put it this way: “Whenever a functioning human brain is present, a human being is alive.” (Goldenring 1985, 200).
Before acquiring this property, brain-life theorists say, a fetus has not yet come into existence; killing it is not like killing an existing human being. Thus aborting a fetus before it acquires brain function is morally permissible. In this article, I contended that this criteria, which “rests in symmetrical view of the beginning and end of human existence” (ibid. 202), defended by Brody, Goldenring and Savulescu, is deeply flawed.²
“Brain death” wrote Eelco F.M. Wijdicks, “is the vernacular expression for irreversible loss of brain function.” He continued,
Brain death is declared when brainstem reflexes, motor responses, and respiratory drive are absent in a normothermic, nondrugged comatose patient with a known irreversible massive brain lesion and no contributing metabolic derangements. (Wijdicks 2002, 20)The irreversible loss of brain function indicates that a patient is dying, or in common parlance "as good as dead," but not that the patient is dead. Don Marquis correctly argued that even if “death is, strictly speaking, defined in terms of the irreversible loss of brain function, the mere absence of brain function is not a sufficient condition for the absence of life.” (Marquis 1996, 8)
Moreover it is not simply the absence of brain function that is in play in pronouncing a person dead, but the irreversible loss of brain function. If a person is reasonably expected to resume or come to have brain function in the future, then that person cannot be pronounced dead. A pre-brain-function fetus is a being that is reasonably expected to come to have brain function, for it “has the natural capacity to bring on the functioning of the brain.” (Varga 1984, 62)
Though I disagree with Peter Singer’s stance on the issue of abortion, I do share his verdict on this view. He correctly concluded that this view is a “convenient fiction that turns an evidently living being into one that legally is not alive. Instead of accepting such fictions, we should recognize that the fact that a being is human, and alive, does not in itself tell us whether it is wrong to take that being’s life.” (Singer 1994, 105)
Brody, Baruch (1975) Abortion and the Sanctity of Human Life: A Philosophical View. Cambridge, MA: MIT Press.
Goldenring, John M. (1985) The brain-life theory: towards a consistent biological definition of humanness. Journal of Medical Ethics Vol. 11:198-204
Marquis, Don (1996) Abortion. Appeared in Donald M. Borchert (2006) ed. Encyclopedia of Philosophy 2nd. Thomson Gale.
Savulescu, J (2002) Abortion, embryo destruction and the future of value argument. Journal of Medical Ethics. Vol. 28: 133-135
Singer, Peter (1994) Rethinking Life & Death: The Collapse of Our Traditional Ethics. New York: St. Martin’s Press
Wijdicks, Eelco F.M. (2002) Brain death worldwide: Accepted fact but no global consensus in diagnostic criteria. Neurology Vol. 58:20-25
Varga, Andrew (1984) The Main Issues in Bioethics. 2nd ed. NY: Paulist Press.
 Goldenring believed that 8-week-old fetus has EEG activity. He boldly asserted, “one cannot advance any logical argument to show that that fetus is not a living human being”(199) from a medical point of view after brain activity.
 One could also argue brain-life theory, as defended by Brody, Goldenring and Savulescu, mistakes the qualitative identity of a developing human being with the numerical identity of being a human being.