Capacity to Reason

Immanuel Kant presented a philosophy known as deontology that is completely based on rational thought. Deontology deals with by describing how one should act based solely on rational calculations and the categorical imperative. The second formulation of the categorical imperative states that one should only act in a way to treat other human beings not only as a means but as ends in themselves. For Kant, living things without reason do not fit under the categorical imperative. Rational beings have value in themselves and therefore no other human has the right to take that life, in effect using them as a means. While I agree with most general principles derived from Kant’s philosophy, there are some problems in specific cases.

One I’ve thought about is brain-dead patients in a hospital. Because a brain-dead patient lacks the ability to formulate the categorical imperative they do not have the ability to reason. Under Kant’s principles, one would be equally just in killing a brain-dead patient as they would weeds in a garden. On the other hand, utilitarian principles would require a felicitous calculation to determine the just thing to do. While feeding tube removal from a brain-dead patient would cause extreme anguish to some, others could a similar distress and fear in knowing that they could be preserved in that state, a state that in effect robs them of a right to die. It would be impossible to balance the pain versus the pleasure in order to decide whether or not removing a feeding tube would be unjust. Hume as well fails to provide any guidance because although some would approve of the removal of a feeding tube, others would be horrified by it.

While deontology provides a concrete answer, where is the line drawn? Abortion advocates often claim that abortion terminates a ball of cells instead of a human being. At some point the fetus acquires a right to life shared with every other person on the planet. The Catholic Church used to point to the “quickening” as the moment the soul entered the body, but now we operate on a rather arbitrary standard of the third trimester. Even at that point though, would Kant have a problem with killing the fetus? The fetus lacks any sort of rational capacity and is unable to formulate his categorical imperative. Several young children would fail this rational capability test, but no one would claim it would be just to kill them. It is likely that Kant would say it is unjust to kill anything that has a capacity to reason. We presume that a fetus will develop cognitive function and become sentient. If that is the case, is abortion ever justifiable under deontology?

Going back to the brain-dead patient though, there is still no way to claim that it is unjust to allow them to die under Kant’s principles. People in comas or sleeping would have the ability to return to cognitive function but if the brain is literally dead how could they possibly return to rational thought? While I have mixed feelings about the result, I do think deontology succeeds in that it provides an answer to a question that neither Mill nor Hume can provide a definitive response.