Science and the Soul
Most people are Cartesian dualists. Like Descartes they believe that body and mind are distinct substances, that there is some essence of a person that is more than just the hundred or two pounds of matter that we can see and touch. Yet as neuroscience advances, the human mind is increasingly understood to be no more than the functioning of a material system. This first became clear in the realms of perception and motor control, where mechanistic models of these processes have been under development for decades. However, such models do not seriously threaten our intuitively "dualist" view of mind and brain. You can still believe in what Arthur Koestler called “the ghost in the machine” and simply conclude that color vision and gait are features of the machine rather than the ghost.
However, as neuroscience begins to reveal the mechanisms of personality and character, this interpretation becomes strained. The brain imaging work reviewed earlier indicates that important aspects of our individuality, including the psychological traits which matter most to us as people, have physical correlates in brain function. Pharmacologic influences on these traits also remind us of the physical bases of human personality. If an SSRI can help us take everyday problems in stride, and if a stimulant can help us meet our deadlines and keep our commitments at work, then mustn’t unflappable temperaments and conscientious characters also be features of people’s bodies? And if so, is there anything about people that is not a feature of their bodies?
A dualist might answer this question by saying that consciousness and spirituality are functions of our immaterial parts. Yet neuroscience is making inroads with these mental phenomena too. Neuroscience research on consciousness began with the study of neurological patients who retained perceptual and memory abilities while professing no conscious awareness of perceiving or remembering and now includes brain imaging research with normal and brain-damaged humans. Although this work has not attempted to account for the private, subjective aspects of consciousness sometimes known as “qualia” it has made progress in accounting for the observable differences between conscious and unconscious cognition.
The relation between religious experience and the brain was first noted in the study of patients with temporal lobe epilepsy, whose seizures were sometimes accompanied by intense religious feelings. Recent neuroimaging research has shown a characteristic pattern of brain activation associated with states of religious transcendence, which is common to Buddhist meditation and Christian prayer (Newberg & D’Aquili, 2001).
Scientists and theologians have long struggled with the challenge of maintaining religious beliefs while accepting science's view of the natural world. The idea that there is somehow more to a person than their physical instantiation runs deep in the human psyche and is a central element in virtually all the world's religions. Neuroscience has begun to challenge this view, by showing that not only perception and motor control, but also character, consciousness and sense of spirituality may all be features of the machine. If they are, then why think there’s a ghost in there at all? The incompatibility between the intuitive or religious view of people and the neuroscience view is likely to have broad social consequences. These are foreshadowed by the highly politicized controversy over evolution and creationism, resulting from the irreconcilable natures of the scientific and fundamentalist Christian views of our origins. Consider that a literal interpretation of Genesis is held by only a minority of religious thinkers, whereas the existence of an immaterial soul is a near universal belief.