The properties we call lifelike that differentiate living cells from inanimate matter result directly from the nucleic acid/protein enzyme mechanisms, and a complete explanation of these mechanisms is possible in terms of the operation in inert chemical ingredients of the ordinary laws of physical science.
The principles of evolution, as we have seen, are accounted for by the laws of physics. In short, the prevailing line of research and theory provides for the origin as well as for the chemistry of life an explanation based entirely on the inexorable workings of the ordinary laws of physical science in the inert ingredients of the earth.
If we ever succeed in completely translating all aspects of the genetic code, we should be able to reduce all the inherited characteristics of an individual—color of the eyes, shape of the nose, contours of the face, pattern of the hairline—from analysis of the nucleic acid from a single heart cell, nerve cell, skin cell, or liver cell!
If there is a purely physical explanation of brain performance, then computerlike structures are in principle capable of precisely duplicating such performance.
All intelligence, whether of computer or brain, is the natural consequence of the powerful symbol-manipulating capabilities of complex switching networks.
There is no logical reason why the definition of physics cannot be broadened to include in its subject matter the subjective conscious experiences of higher animals.
We have failed to discover any aspect of life—whether related to the origin of organisms, to their physical properties, to behavior, to intelligence, or to consciousness—whose explanation appears today to lie beyond the ultimate capabilities of physical science. In the late 1960s we seem justified in the broadest possible application of what may be called the central thesis of physical biology: that a single body of natural laws operating on a single set of material particles completely accounts for the origin and properties of living organisms as well as nonliving aggregations of matter and man-made structures. Accordingly, man is essentially no more than a complex machine.
Men are always reluctant to abandon any of the anthropocentric legends they traditionally employ to bolster their feelings of self-importance, and the concept of the machinelike nature of man is incompatible with a long-cherished belief in human uniqueness.
Among the wires and transistors of existing electronic computers there already flickers the dim glimmering of the same kind of personal awareness as that which has become, for man, his most precious possession.
If the trend of scientific discovery we have discussed continues until the machinelike nature of man finally comes to be widely accepted, there could ensue important changes in man’s attitudes and institutions.
Man’s dominance over other species is in large part the result of his social attributes—only by living and working together is it possible for men to secure the advantages flowing from knowledge obtained by others and for successive generations to progress by accumulation of such knowledge. But living and working together is impossible unless each individual is willing to accept some restraints on his own activities for the good of society, that is, to exhibit moral behavior.
Because of our need to feel unique, the idea of the fundamental irreconcilability of life processes with the principles of physical science has always been almost automatically accepted as true.
Men who know they are machines should be able to bring a higher degree of objectivity to bear on their problems than machines that think they are Men.