Biology | Page 2

lower ones, but also the still larger question of the primordial
relation of living things to the non-living world. Here is involved the
possibility so strikingly expressed many years ago by Tyndall in that
eloquent passage in the Belfast address, where he declared himself
driven by an intellectual necessity to cross the boundary line of the
experimental evidence and to discern in non-living matter, as he said,
the promise and potency of every form and quality of terrestrial life.
This intellectual necessity was created by a conviction of the continuity
and consistency of natural phenomena, which is almost inseparable
from the scientific attitude towards nature. But Tyndall's words stood
after all for a confession of faith, not for a statement of fact; and they
soared far above the terra firma of the actual evidence. At the present
day we too may find ourselves logically driven to the view that living
things first arose as a product of non-living matter. We must fully
recognize the extraordinary progress that has been made by the chemist
in the artificial synthesis of compounds formerly known only as the
direct products of living protoplasm. But it must also be admitted that
we are still wholly without evidence of the origin of any living thing, at
any period of the earth's history, save from some other living thing; and
after more than two centuries Redi's aphorism omne vivum e vivo
retains to-day its full force. It is my impression therefore that the time
has not yet come when hypotheses regarding a different origin of life
can be considered as practically useful.

If I have the temerity to ask your attention to the fundamental problem
towards which all lines of biological inquiry sooner or later lead us it is
not with the delusion that I can contribute anything new to the
prolonged discussions and controversies to which it has given rise. I
desire only to indicate in what way it affects the practical efforts of
biologists to gain a better understanding of the living organism,
whether regarded as a group of existing phenomena or as a product of
the evolutionary process; and I shall speak of it, not in any abstract or
speculative way, but from the standpoint of the working naturalist. The
problem of which I speak is that of organic mechanism and its relation
to that of organic adaptation. How in general are the phenomena of life
related to those of the non-living world? How far can we profitably
employ the hypothesis that the living body is essentially an automaton
or machine, a configuration of material particles, which, like an engine
or a piece of clockwork, owes its mode of operation to its physical and
chemical construction? It is not open to doubt that the living body is a
machine. It is a complex chemical engine that applies the energy of the
food-stuffs to the performance of the work of life. But is it something
more than a machine? If we may imagine the physico-chemical
analysis of the body to be carried through to the very end, may we
expect to find at last an unknown something that transcends such
analysis and is neither a form of physical energy nor anything given in
the physical or chemical configuration of the body? Shall we find
anything corresponding to the usual popular conception--which was
also along the view of physiologists--that the body is "animated" by a
specific "vital principle," or "vital force," a dominating "archæus" that
exists only in the realm of organic nature? If such a principle exists,
then the mechanistic hypothesis fails and the fundamental problem of
biology becomes a problem sui generis.
In its bearing on man's place in nature this question is one of the most
momentous with which natural science has to deal, and it has occupied
the attention of thinking men in every age. I cannot trace its history, but
it will be worth our while to place side by side the words of three of the
great leaders of modern scientific and philosophic thought. The saying
has been attributed to Descartes, "Give me matter and I will construct
the world"--meaning by this the living world as well as the non-living;

but Descartes specifically excepted the human mind. I do not know
whether the great French philosopher actually used these particular
words, but they express the essence of the mechanistic hypothesis that
he adopted. Kant utterly repudiated such a conception in the following
well known passage: "It is quite certain that we cannot become
adequately acquainted with organized creatures and their hidden
potentialities by means of the merely mechanical principles of nature,
much less can we explain them; and this is so certain that we may
boldly assert that it is absurd for man even to make such an attempt or
to hope