But how can we conceive of the mind-body relationship in accordance with these two statements? Here a helpful analogy may be found in the theory of fields in the physical sciences—the magnetic field and the gravitational field, for example. In both of these cases the field is certainly produced by a generating physical object, but it is also clear that the field is distinct from the object, as is shown by the fact that the object is sharply localized whereas the field spreads out for an indefinite distance in all directions. So, we may surmise, the “field of consciousness” or “soul-field” is generated by the appropriately complex organic functioning of the human brain. And just as the fields of physics continually interact with the generating body (as in an electric motor or generator), so the “conscious field” continually interacts with its own generating organism.
Of course the distinguishing characteristics of human beings are not exemplified by the fields of physics. What we can say, however, is this: Just as electrical, magnetic and gravitational fields function in accordance with the laws of their respective natures, so the soul-field functions in accordance with its own inherent natural potentialities, which include, among other things, both rational autonomy and moral freedom. This view may be termed emergentism, in recognition of the appearance or “emergence” of the soul-field as a result of the organization and functioning of the brain and nervous system.
To make this clearer, certain questions need to be answered. What exactly is this field supposed to be? Is it a thing—or, as philosophers say, a substance? The answer is that the conscious field is to be thought of as a concrete, individual, continuing entity, and thus a substance in at least one sense of that term. Is the soul-field a “mental substance,” like the mind or soul of dualism? It is certainly mental in that it is characterized by mental properties such as feeling, choosing and imagining, but it does not share other characteristics of the dualist’s mental substance. The soulfield has spatial location and extension, and it is also physically divisible; under certain circumstances dividing an organism into parts may result in the division of the associated conscious field. The gulf between mental and physical simply is not as wide for emergentism as it is for dualism; that is a principal difference between the views. But isn’t emergentism, after all, a kind of dualism? Perhaps in a sense it is, but it is sufficiently different from the common types of dualism (for instance, the theories of René Descartes and Thomas Aquinas) that it is useful to designate it by a name of its own.
A theory of this kind, while certainly not proven by scientific data, seems to be entirely consistent with all scientific findings to date. And it clearly avoids the major disadvantages noted in the other theories. Unlike materialism, it avoids simply equating a person with her body, and it recognizes the distinctive aspects of human functioning which are negated if it is claimed that human activity is entirely explainable in terms of physics and chemistry. Like dualism, it affirms interaction between a person’s mind and her body, but such interaction is far more credible and intelligible if it is interaction between a field and its generating body than if it is interaction between two substances which are entirely diverse in their nature and origin. And emergentism readily accepts the multiple dependencies of the mind on the biological functioning of the brain and nervous system; for emergentism (unlike dualism) this is what would naturally be expected. Furthermore, the problem about the souls of animals is on this view a nonproblem: Of course the beasts have souls, but souls that are less complex and developed than those of human beings because they are generated by less complex and less developed nervous systems.