One of the great ethical achievements
of early Christianity and some of the other
religions was a recognition in principle of the brotherhood of man. The first grand
lesson learned from evolution was that of the unity of life. Not only are all men
brothers; all living things are brothers in the very real, material sense that all have
arisen from one source and been developed within one process.
We are part of nature and we are related
to every other organism that has existed,
or that does or will exist on the earth. But we are more nearly related to some than
to others. It is obvious that man is an animal and not a plant, which is a taxonomic
way of saying that he is more closely related to all animals than to any plant.
Among the animals it is equally obvious that, in the same sense, man is a
vertebrate and not an invertebrate. Among vertebrates he is a mammal, not one of
the various sorts of "fishes," an amphibian, a reptile, or a bird. Among mammals he
is a primate, a member of the Order Primates and of no other of the numerous
mammalian orders.
As the degrees of relationship are narrowed,
the distinctions become less and their
significance becomes less obvious. The general position of Homo sapiens within
the animal kingdom, within the vertebrate subphylum, and within the mammalian
class is absolutely established and beyond any doubt.The exact position within the
primate order and the detailed relationship to each of the other primates, living and
fossil, are not yet known with complete precision. Such questions as whether the
gorilla, the tarsier, or some other living primate is the closest surviving branch from
the human ancestry have no essential bearing on the nature of man or on man's
place in nature.
Man's intellectual, social, and spiritual
natures are altogether exceptional among
animals in degree, but they arose by organic evolution. It has also been shown that
purpose and plan are not characteristic of organic evolution and are not a key to
any of its operations. Man was certainly not the goal of evolution, which evidently
had no goal. He was not planned, in an operation wholly planless. He is not the
ultimate in a single constant trend toward higher things, in a history of life with
innumerable trends, none of them constant, and some toward the lower rather than
the higher. Is his place in nature, then, that of a mere accident, without significance?
The affirmative answer that some have felt constrained to give is another example
of the "nothing but" fallacy. The situation is as badly misrepresented and the lesson
as poorly learned when man is considered nothing but an accident as when he is
considered as the destined crown of creation. His rise was neither insignificant nor
inevitable. Man did originate after a tremendously long sequence of events in which
both chance and orientation played a part. Not all the chance favored his
appearance, none might have, but enough did. Not all the orientation was in his
direction, it did not lead unerringly human- ward, but some of it came this way. The
result is the most highly endowed organization of matter that has yet appeared on
the earth—and we certainly have no good reason to believe there is any higher in
the universe. To think that this result is insignificant would be unworthy of that high
endowment, which includes among its riches a sense of values.
