Human Dignity and Bioethics

The Mystery of the Human Soul | 63
Scientific Materialism: Man as Complex Machine and
as Master of the Machine
When we speak about “human dignity” or “the dignity of man,” we
usually mean the special moral status of human beings in the natural
universe as well as the respect due to individual humans because of
their essential humanity. 1 The central point of human dignity is that
membership in the human species is somehow special and therefore
a matter of moral significance that includes duties and rights which
most cultures recognize and which reason can justify as objectively
good. Interestingly, the most common objection to respecting human
dignity is not moral relativism but the alleged “truth” of scientific
materialism that man is a complex machine without soul or
special moral status and we should simply “get over it” for our own
good. The argument I will make is that most scientific materialists ultimately
find this view untenable and restore the soul in some fashion
to account for morality and their own scientific activities.
This pattern can be seen in the philosophy of Thomas Hobbes,
one of the original spokesmen for scientific materialism. 2 Hobbes argued
that the universe is nothing more than “bodies in motion” and
that everything happens by one body touching another body without
action-at-a-distance by immaterial causes, such as the spirits and
ghosts of popular religion or the intangible substances of medieval
Scholasticism or the forms and essences of Aristotle. Following the
logic of materialism, Hobbes sought to explain all of man’s behavior
by a stimulus-response model of “appetites and aversions” in which
the senses receive motions from external bodies, the signals are passed
to the heart and brain, an image is formed that triggers a response,
and the body moves accordingly. In this view, the mind is just a processor
of sense images, and complex human emotions are reduced
to selfish passions—especially the irrational desire for power and the
rational fear of death. Hobbes denied that human beings have souls
and said the will is not free to choose but is merely “the last appetite
in deliberation.” He even used the metaphor of an “engine” driven by
springs and wheels to describe man at the beginning of Leviathan in
order to emphasize his mechanical conception of human behavior.
In addition, Hobbes explicitly rejected Descartes’s view that the
universe is made of two distinct substances, material bodies and