Ethics and Personhood: Some Issues in Contemporary Neurological Science and Technology

By Dr. David L. Perry

Adapted from a presentation at a "Works in Progress" forum sponsored by the Center for Biomedical Ethics at Stanford University on December 11, 2001.

I. The mind-brain puzzle

Modern advances in neurological science and technology pose profound challenges for our traditional concepts of the human person: they generate metaphysical and moral questions about beings at the edges of human life, from embryos that are not yet conscious, to persons who have lost their capacity for rational thought or have become permanently unconscious.’ll begin by framing these issues in the context of an ancient puzzle that has been the subject of much philosophical and religious debate: What is the relationship between the soul and the body (or the mind and the brain)? We take for granted the intimate connection between our minds and bodies. It’s difficult to imagine our selves as disconnected from the particular bodies we have. But we also have a strong intuition that consciousness is a truly extraordinary thing in nature.

Many people have thought that the only way to account for the qualitative distinction between brain and mind is to regard them as fundamentally different substances, one material, the other immaterial. The 17th-century philosopher Rene Descartes was one of the most famous proponents of that view, but religious traditions have affirmed similar beliefs for millennia. The attraction of such a concept is obvious: if our soul/mind is not a material thing, then it’s conceivably immortal. The soul might survive the death of the body in an afterlife, as the Jewish, Christian and Islamic religions teach. Or the soul might be reincarnated through a potentially unlimited succession of living bodies, as the Hindu or Buddhist traditions hold.

But there turn out to be serious conceptual problems with the belief that the mind and body are essentially different substances. If the soul is immaterial, then it can have no location in space, and thus cannot be contained by any physical brain or body. More importantly, an immaterial mind could never interact with material things or events like the electrical impulses and biochemical activities occurring constantly in and between our neural cells. The belief that the soul is immaterial also flies directly in the face of our daily experiences of being conscious of the physical world through our bodily senses of sight, hearing and touch. An immaterial mind could not be our mind; it would be utterly disconnected from our embodied experience and self-identity.

(Note also that immaterial ghosts/spirits could never be seen, heard or felt. On the other hand, if they’re asserted instead to be material beings, then their presence ought to be measurable through controlled scientific tests—none of which has ever proven their existence. See Schick & Vaughn 1999b.)

Modern neuroscience is systematically revealing the correlations between mental states and brain states, even if it hasn’t yet shown their causal relations nor proven that we’ll ever be able to express mental events entirely in electrical and biochemical terms. The most promising philosophical approach to the mind-brain puzzle—and one that is fully compatible with modern neuroscience—is known as "property dualism." This theory envisions the mind as an emergent property of individually unconscious neural cells when they interact in complex ways, analogous to wetness as an emergent property of water molecules, or life as an emergent property of amino acid molecules which are individually lifeless (Searle 1992; Schick & Vaughn 1999a). I cannot do justice to that theory in this short article. Suffice it to say that some appreciation of brain functioning is essential to understanding what it takes to have a mind.

II. Who or what is a person?

continue

do site scu.edu