Are Persons Just an Illusion?

Neuroscience and philosophy clash.

Neuroscientists Martha Farah and Andrea Heberlein, in the January issue of the American Journal of Bioethics (subscription link), wonder if empirical insights from their discipline can naturalize personhood. In other words, they explore the notion that a person is a "natural kind" and "seeks objective and clear-cut biological criteria that correspond reasonably well with most peoples' intuitions about personhood. These criteria could then be substituted for intuition in those cases where intuitions fail to agree." This is an important issue, because trying to determine who is and is not a person figures in our ethical and policy debates over the status of the brain dead, embryos, and primates.

Farah and Heberlein proceed to discuss the neuroscientific evidence for the existence of a separate network of brain systems that automatically identifies persons as opposed to non-persons. Data from brain trauma patients and functional magnetic resonance imaging (fMRI), in which sections of the brain "light up" when experiencing specific stimuli, have identified a candidate person recognition network in the brain. This personhood network is triggered by stimuli such as human-like faces, bodies, or contingent behaviors. (Contingent behavior is activity that looks like it is responsive to the outside environment and purposeful.)

The authors argue that the person network is innate and point out that newborns within 30 minutes of birth tend to track face-like patterns with their eyes more than they do other shapes of comparable symmetry or complexity. Noting that the human face is a powerful trigger for the personhood network, Farah and Heberlein, speculate that "this may be what makes it hard for many of us to dismiss the personhood of a vegetative patient or a fetus."

Farah and Heberlein contend that the personhood brain network evolved because as an intensely social species, our ancestors' survival was enhanced by understanding the beliefs, motivations and personalities of others. They also speculate that the cost of ascribing intentions to non-intentional systems might have been far less than the cost of failing to recognize intentions in intentional systems. Thus the brain's personhood network may err on the side of activating too often. (This may account of religious belief systems that attributed intentions to the sun, rain, rivers, volcanoes and the like. Interestingly, the less humanity has attributed intentions to natural phenomena, the greater control we have obtained over them—or is it the other way around?)

Farah and Heberlein then claim that since the personhood network makes frequent mistakes and often attributes personhood to non-intentional systems that "suggests the personhood is a kind of illusion." They conclude, "If personhood is not really in the world, then there is no fact of the matter concerning the status of a given being as a person or not, and there is no point to the philosophical or bioethical program of seeking objective criteria for personhood more generally because there is none."

This claims too much. Fortunately, the Journal publishes a number of thoughtful responses to Farah and Heberlein. One of the more devastating is by University of California, San Diego neurophilosopher Patricia Churchland. "Are there no mountains, no vegetables, no weeds, and no diseases?," she begins. Her point is that there are no precise criteria, or "natural kinds" that completely specify what a mountain, a vegetable, a weed or a disease is. Lambs quarter can either be a salad green or weed depending on how various gardeners regard it. Is obesity really a disease in quite the same way as smallpox? Yet despite the lack of precise criteria for all kinds of things out in the world (matters of fact, if you will), we manage to know what we're talking about and get along quite well.

As Christian Perring, a philosopher from Dowling College in Oakdale, New York, points out there is a great deal of agreement on what constitutes personhood. These include attributes such as rationality, memory, ability to self-reflect, intelligence, and a concept of self. "We are good at distinguishing persons from non-persons in most ordinary circumstances," writes Dowling. It is the extraordinary circumstances that modern medicine engenders—embryos in Petri dishes, severe Alzheimer's patients, anencephalic newborns, early fetuses, and patients in persistent vegetative state—that are problematic for many people. For example, it is clearly the case that prolife activists hope to activate the personhood networks of women seeking abortions by requiring them to view ultrasound images of their fetuses before undergoing the procedure.

University of Maryland philosopher Mark Sagoff makes the extremely interesting point that the notion that personhood is somehow a moral trump that demands that others recognize a being's rights is an historically new concept. "The idea that every human being prima facie is entitled to equal respect and concern under rules fair to all seems to depend not on hard-wired biological factors but on contingent historical variables," writes Sagoff. Human history, after all, is replete with tribes who kill outsiders, men who kill "dishonored" women, believers who kill and torture infidels, and so forth.

I believe that Dartmouth College philosopher Adina Roskies is right when she suggests "knowing that one part of our biological system for identifying persons is automatically entrained and subject to error should make us more cognizant of its operation and more skeptical of its output as we engage in the countless moral decisions we make each day." If Farah and Heberlein have correctly identified an innate personhood network in our brains, they will have helped free us from its mandates, just as other natural scientists freed us from our misconceptions about the sources of disease and rain. We are not just slaves to our brains' personhood networks—we can use our rationality to figure out which entities count as persons and which do not. We will most likely conclude that personhood is a continuum, not an all or nothing property. Just where to draw moral lines along that continuum will be a long hard fought debate, but as Sagoff has pointed out moral progress can be made. In the end, Farah and Heberlein are wrong, persons are as real as mountains, diseases, weeds, pets and daylight.

Ronald Bailey is Reason's science correspondent. His book Liberation Biology: The Scientific and Moral Case for the Biotech Revolution is now available from Prometheus Books.

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