



Produced by D. R. Thompson





LECTURES ON EVOLUTION

ESSAY #3 FROM "SCIENCE AND HEBREW TRADITION"


By Thomas Henry Huxley




I. THE THREE HYPOTHESES RESPECTING THE HISTORY OF NATURE

We live in and form part of a system of things of immense diversity
and perplexity, which we call Nature; and it is a matter of the deepest
interest to all of us that we should form just conceptions of the
constitution of that system and of its past history. With relation to
this universe, man is, in extent, little more than a mathematical point;
in duration but a fleeting shadow; he is a mere reed shaken in the winds
of force. But as Pascal long ago remarked, although a mere reed, he is
a thinking reed; and in virtue of that wonderful capacity of thought,
he has the power of framing for himself a symbolic conception of the
universe, which, although doubtless highly imperfect and inadequate as
a picture of the great whole, is yet sufficient to serve him as a chart
for the guidance of his practical affairs. It has taken long ages of
toilsome and often fruitless labour to enable man to look steadily at
the shifting scenes of the phantasmagoria of Nature, to notice what is
fixed among her fluctuations, and what is regular among her apparent
irregularities; and it is only comparatively lately, within the last few
centuries, that the conception of a universal order and of a definite
course of things, which we term the course of Nature, has emerged.

But, once originated, the conception of the constancy of the order of
Nature has become the dominant idea of modern thought. To any person who
is familiar with the facts upon which that conception is based, and
is competent to estimate their significance, it has ceased to be
conceivable that chance should have any place in the universe, or that
events should depend upon any but the natural sequence of cause and
effect. We have come to look upon the present as the child of the past
and as the parent of the future; and, as we have excluded chance from a
place in the universe, so we ignore, even as a possibility, the notion
of any interference with the order of Nature. Whatever may be men's
speculative doctrines, it is quite certain that every intelligent person
guides his life and risks his fortune upon the belief that the order of
Nature is constant, and that the chain of natural causation is never
broken.

In fact, no belief which we entertain has so complete a logical basis as
that to which I have just referred. It tacitly underlies every process
of reasoning; it is the foundation of every act of the will. It is based
upon the broadest induction, and it is verified by the most constant,
regular, and universal of deductive processes. But we must recollect
that any human belief, however broad its basis, however defensible it
may seem, is, after all, only a probable belief, and that our widest and
safest generalisations are simply statements of the highest degree of
probability. Though we are quite clear about the constancy of the order
of Nature, at the present time, and in the present state of things, it
by no means necessarily follows that we are justified in expanding this
generalisation into the infinite past, and in denying, absolutely, that
there may have been a time when Nature did not follow a fixed order,
when the relations of cause and effect were not definite, and when
extra-natural agencies interfered with the general course of Nature.
Cautious men will allow that a universe so different from that which we
know may have existed; just as a very candid thinker may admit that a
world in which two and two do not make four, and in which two straight
lines do inclose a space, may exist. But the same caution which forces
the admission of such possibilities demands a great deal of evidence
before it recognises them to be anything more substantial. And when
it is asserted that, so many thousand years ago, events occurred in a
manner utterly foreign to and inconsistent with the existing laws of
Nature, men, who without being particularly cautious, are simply honest
thinkers, unwilling to deceive themselves or delude others, ask for
trustworthy evidence of the fact.

Did things so happen or did they not? This is a historical question, and
one the answer to which must be sought in the same way as the solution
of any other historical problem.

So far as I know, there are only three hypotheses which ever have been
entertained, or which well can be entertained, respecting the past
history of Nature. I will, in the first place, state the hypotheses,
and then I will consider what evidence bearing upon them is in our
possession, and by what light of criticism that evidence is to be
interpreted.

Upon the first hypothesis, the assumption is, that phenomena of Nature