Skip to main content

Full text of "Man In The Modern World"

Higher Primates have yet another prerequisite of human intelli-
gence—they are all gregarious. Speech, it is obvious, could never have
been evolved in a solitary type. And speech is as much the physical
basis of conceptual thought as is protoplasm the physical basis of life.
For the passage, however, of the critical point between subhuman
and human, between the biological subordination and the biological
primacy of intelligence, between a limited and a potentially unlimited
tradition—for this it was necessary for the arboreal animal to de-
scend to the ground again. Only in a terrestrial creature could fully
erect posture be acquired; and this was essential for the final con-
version of the arms from locomotor limbs into manipulative hands.
Furthermpre, just as land life, ages previously, had demanded and
developed a greater variety of response than had been required in the
water, so now it did the same in relation to what had been required
in the trees. An arboreal animal could never have evolved the skill
of the hunting savage, nor ever have proceeded to the domestication
of other animals or to agriculture.
We are now in a position to define the uniqueness of human evolu-
tion. The essential character of man as a dominant organism is con-
ceptual thought. And conceptual thought could have arisen only in
a multicellular animal, an animal with bilateral symmetry, head and
blood system, a vertebrate as against a mollusc or an arthropod, a
land vertebrate among vertebrates, a mammal among land verte-
brates. Finally, it could have arisen only in a mammalian line which
was gregarious, which produced one young at a birth instead of
several, and which had recently become terrestrial after a long period
of arboreal life.
There is only one group of animals which fulfils these conditions—
a terrestrial offshoot of the higher Primates. Thus not merely has
conceptual thought been evolved only in man: it could not have been
evolved except in man. There is but one path of unlimited progress
through the evolutionary maze. The course of human evolution is
as unique as its result. It is unique not in the trivial sense of being a
different course from that of any other organism, but in the pro-
founder sense of being the only path that could have achieved the
essential characters of man. Conceptual thought on this planet is
inevitably associated with a particular type of Primate body and
Primate brain.
A further property of man in which he is unique among higher
animals concerns his sexual life. Man is prepared to mate at any
time: animals are not. To start with, most animals have a definite
breeding season; only during this period are their reproductive