Soul

The various conceptions of the soul include but are not restricted to (a) a first principle or fundamental source of life found in a living thing, (b) a spiritual substance responsible for a thing's being alive and perhaps capable of existing apart from the body after death, and (c) the seat of the psychological operations of a being capable of conscious existence. A given explanation of the soul may be in response to one or more of these conceptions. For example, some have conceived of the soul as a spiritual substance that fits all three of these categories, whereas others have spoken of the soul as a material entity that fits only the first and, perhaps, third categories. In addition to having three notions of soul, further confusion arises because, while some analysts have treated the soul as a physical part of the body, contemporary materialists who believe that something physical exists and fits the first and third categories refrain from speaking of a soul.

This discussion is focused on the conception of soul as a first principle or source of life found in a living thing. A test for what fills the role of the first principle is to inquire as to what is no longer present at the time when what had been a living body ceases to be alive. Three approaches are common.

• 1.
  The soul may be taken to be a spatially extended physical object. There has been a common belief in ghosts as spatially extended ethereal beings that depart from the body at death. Alternatively, ancient Greek atomists, such as Democritus, held that the soul is made up of small spherical atoms, and when these depart, bodily death occurs. Plato spoke of a worry that some people had that the soul of one who dies on a windy night might be scattered and dispersed, precluding the possibility of its continued existence after death. If one conceives of the soul as the seat of psychological operations, then one might locate the soul in a part of the body. In the past, the heart was sometimes treated as the seat of emotions; today analysts are inclined to treat the brain as the seat of the emotions, consciousness, and intellect.
• 2.
  The soul is held to be a nonphysical spiritual substance that gives life to a living organism. This doctrine, “substance dualism” or “Cartesian dualism,” is most closely associated with the philosophers Plato and Descartes. Descartes characterizes the nonphysical nature of the soul in terms of it as being a thinking thing that is not spatially extended—for Descartes, thinking involves any conscious process of which there is immediate awareness. Descartes's narrow conception identified the soul with the mind and held that it is the principle of conscious life. Nonhuman life, Descartes believed, can be fully accounted for mechanistically without appeal to the soul; we only need the soul/mind to explain the existence of a thinking being. It was a notorious feature of Descartes's philosophy that he thought nonhuman animals are altogether lacking in consciousness. It has also been common for substance dualists to hold that a nonhuman animal can possess a nonmaterial soul. Those, not in the Buddhist tradition, who accept the view that reincarnation occurs through a transmigration of the soul appear to be substance dualists.
• 3.
  A third approach has its roots in Aristotle's account of the soul. Aristotle held that physical things are a composite of matter and form. A thing is what it is in virtue of its form. Thus, due to a change in form, the same matter may at one time be grape juice, at another time be wine, and yet at a third time be vinegar. Of course, a thing need not retain the same matter to remain in existence; a living thing undergoing metabolism will exchange matter with its environment while remaining the same individual. What makes a living thing alive is that it has a substantial form in virtue of which it is a living thing of a given kind. [Page 882]Aristotle takes the substantial form of a living thing to be its soul. Thus, for Aristotle, all living things have a soul. This does not entail that all living things have some form of consciousness, but they must have some vital functions to be alive. In virtue of its soul (or form), different grades of living things have different vital capacities. A plant has capacities to grow, take in nourishment, and reproduce in virtue of having a formal organization as a plant. An animal has the previous mentioned capacities plus the capacity to move about and have sensation in virtue of having an animal soul. A human animal also has rational capacities by virtue of its human soul.

Immortality and Personal Identity

Assuming that continued existence of a self or an individual living being requires the continued existence of its soul, there is a close connection between theories of the soul and the question of whether survival of death, or even immortality, is possible. If the soul is not distinct from the body, then it is hard to see how there could be survival of bodily death without a resuscitation or resurrection of the body. Similar considerations apply if the soul is a part of the body: it is easy to see how there could be survival of the death of the soul-part by a resuscitation or resurrection of the soul-part. Once there has been dissolution of the body, it is difficult to see what could count as a resurrection of the same living being. This problem is a special case of what philosophers call the problem of personal identity over time.

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