The hazards of the future of the race must be quite different from
those I have been considering. They are the hazards incident to an
exceptional being upon this earth--a being that takes his fate in
his own hands in a sense that no other creature does.
Man has partaken of the fruit of the Tree of Good and Evil, which
all the lower orders have escaped. He knows, and knows that he
knows. Will this knowledge, through the opposition in which it
places him to elemental nature and the vast system of artificial
things with which it has enabled him to surround himself, cut short
his history upon this planet? Will Nature in the end be avenged for
the secrets he has forced from her? His civilization has doubtless
made him the victim of diseases to which the lower orders, and even
savage man, are strangers. Will not these diseases increase as his
life becomes more and more complex and artificial? Will he go on
extending his mastery over Nature and refining or suppressing his
natural appetites till his original hold upon life is fatally
enfeebled?
It seems as though science ought to save man and prolong his stay on
this planet,--it ought to bring him natural salvation, as his
religion promises him supernatural salvation. But of course, man's
fate is bound up with the fate of the planet and of the biological
tree of which he is one of the shoots. Biology is rooted in geology.
The higher forms of life did not arbitrarily appear, they flowed out
of conditions that were long in maturing; they flowered in season,
and the flower will fall in season. Man could not have appeared
earlier than he did, nor later than he did; he came out of what went
before, and he will go out with what comes after. His coming was
natural, and his going will be natural. His period had a beginning,
and it will have an end. Natural philosophy leads one to affirm
this; but of time measured by human history he may yet have a lease
of tens of thousands of years.
The hazard of the future is a question of both astronomy and
geology. That there are cosmic dangers, though infinitely remote,
every astronomer knows. That there are collisions between heavenly
bodies is an indubitable fact, and if collisions do happen to any,
allow time enough and they must happen to all. That there are
geologic dangers through the shifting and crumpling of the earth's
crust, every geologist knows, though probably none that could wipe
out the whole race of man. The biologic dangers of the past we have
outlived--the dangers that must have beset a single line of descent
amid the carnival of power and the ferocity of the monster reptiles
of Mesozoic times, and the wholesale extinction of species that
occurred in different geologic periods.
Nothing but a cosmic catastrophe, involving the fate of the whole
earth, could now exterminate the human race. It is highly improbable
that this will ever happen. The race of man will go out from a slow,
insensible failure, through the aging of the planet, of the
conditions of life that brought man here. The evolutionary process
upon a cooling world must, after the elapse of a vast period of
time, lose its impetus and cease.