Person

Paul W. Taylor, Respect for Nature: A Theory of Environmental Ethics. Princeton, 1986. Pages 144-145 “Are the mind and body of a person two substances, that is, two distinct things having entirely different sorts of properties? According to Cartesian metaphysics the mind is a thinking substance that does not take up any space and hence cannot be located anywhere. We must not picture it as something that exists inside the body, nor is it to be found somewhere outside the body. It is simply nonspatial. The body, on the other hand, is a solid three-dimensional object that lacks the properties of thought and consciousness. If we think of a person’s mind and body in these terms we are confronted with an unsolvable problem of how the two substances are connected with each other to form one individual person. When someone decides to do something and then does it, the Cartesian view is that the person’s mind causes certain motions to take place in that same person’s body. But how can a nonphysical, nonspatial entity produce changes in the physical state of something in space? Descartes thought that the place where the mind directly causes changes in the body is at a certain point in the brain. Not only does this seem to contradict the idea that the mind cannot be located in space, but it makes the connection between mind and body incomprehensible since it requires that chemical transformations in a person’s brain occur as the direct effect of something that has no chemical properties. Yet a person’s deciding to do something and then doing it is an everyday occurrence. Because the metaphysical dualism of mind and matter precludes any clear or coherent account of such an occurrence, as well as of other equally commonplace occurrences, most contemporary philosophers have rejected the Cartesian concept of a person as a nonphysical substance somehow connected with a physical substance. A second problem has to do with the Cartesian way of distinguishing between human beings and other animals. Since humans are held to be both physical and mental beings while animals are only physical, there is an absolute metaphysical gulf between them. They are utterly distinct and completely different kinds of entities. Now this total separation of humans from animals seems to fly in the face of recent biological knowledge of humans and certain closely related mammals like the primates. Not only do such mammals give every evidence of the capacity to feel pleasure and pain, but both their external behavior and the internal structure of their brains and nervous systems indicate that they can experience many kinds of emotions, including fear, anger, excitement, anxiety, and even concern for others in their group. They appear to possess certain powers of intelligence and thought. … When we bring into consideration the additional knowledge we have gained concerning our genetic makeup and the evolutionary origins of human life, as well as the findings of biochemistry concerning molecular changes in human and animal cells, the similarity between ourselves and other animals cannot be denied. Although there are differences do not seem to support the Cartesian view that there is a deep and fundamental separation of ourselves from animals grounded on the absolute divergence of the two ontological categories we and they belong to. Cartesian dualism cannot accommodate the whole trend of recent scientific understanding of humans as biological beings.”