Some things come and some things arise; things that already exist may
come, but potential things arise; my friend comes to visit me, the tide
comes up the river, the cold or hot wave comes from the west; but the
seasons, night and morning, health and disease, and the like, do not
come in this sense; they arise. Life does not come to dead matter in
this sense; it arises. Day and night are not traveling round the earth,
though we view them that way; they arise from the turning of the earth
upon its axis. If we could keep up with the flying moments,--that is,
with the revolution of the earth,--we could live always at sunrise, or
sunset, or at noon, or at any other moment we cared to elect. Love or
hate does not come to our hearts; it is born there; the breath does not
come to the newborn infant; respiration arises there automatically. See
how the life of the infant is involved in that first breath, yet it is
not its life; the infant must first be alive before it can breathe. If
it is still-born, the respiratory reaction does not take place. We can
say, then, that the breath means life, and the life means breath; only
we must say the latter first. We can say in the same way that
organization means life, and life means organization. Something sets up
the organizing process in matter. We may take all the physical elements
of life known to us and jumble them together and shake them up to all
eternity, and life will not result. A little friction between solid
bodies begets heat, a little more and we get fire. But no amount of
friction begets life. Heat and life go together, but heat is the
secondary factor.
Life is always a vanishing-point, a constant becoming--an unstable
something that escapes us while we seem to analyze it. In its nature or
essence, it is a metaphysical problem, and not one of physical science.
Science cannot grasp it; it evaporates in its crucibles. And science is
compelled finally to drive it into an imaginary region--I had almost
said, metaphysical region, the region of the invisible, hypothetical
atoms of matter. Here in the mysteries of molecular attraction and
repulsion, it conceives the secret of life to lie.
"Life is a wave," says Tyndall, but does not one conceive of something,
some force or impulse in the wave that is not of the wave? What is it
that travels along lifting new water each moment up into waves? It is a
physical force communicated usually by the winds. When the wave dies
upon the shore, this force is dissipated, not lost, or is turned into
heat. Why may we not think of life as a vital force traveling through
matter and lifting up into organic life waves in the same way? But not
translatable into any other form of energy because not derivable from
any other form.
Every species of animal has something about it that is unique and
individual and that no chemical or physiological analysis of it will
show--probably some mode of motion among its ultimate particles that is
peculiar to itself. This prevents cross-breeding among different species
and avoids a chaos of animal and vegetable forms. Living tissues and
living organs from one species cannot be grafted upon the individuals
of another species; the kidney of a cat, for instance, cannot be
substituted for that of a dog, although the functions and the anatomy of
the two are identical. It is suggested that an element of felineness and
an element of canineness adhere in the cells of each, and the two are
antagonistic. This specific quality, or selfness, of an animal pervades
every drop of its blood, so that the blood relationship of the different
forms may be thus tested, where chemistry is incompetent to show
agreement or antagonism. The reactions of life are surer and more subtle
than those of chemistry. Thus the blood relationship between birds and
reptiles is clearly shown, as is the relationship of man and the
chimpanzee and the orang-outang. The same general fact holds true in the
vegetable world. You cannot graft the apple upon the oak, or the plum
upon the elm. It seems as if there were the quality of oakness and the
quality of appleness, and they would not mix.
The same thing holds among different chemical compounds. Substances
which have precisely the same chemical formulæ (called isomers) have
properties as widely apart as alcohol and ether.
If chemistry is powerless to trace the relationship between different
forms of life, is it not highly improbable that the secret of life
itself is in the keeping of chemistry?
Analytical science has reached the end of its tether when it has
resolved a body into its constituent elements. Why or how these elements
build up a man in the one case, and a monkey in another, is beyond its
province to say. It can deal with all the elements of the living body,
vegetable and animal; it can take them apart and isolate them in
different bottles; but it cannot put them together again as they were in
life. It knows that the human body is built up of a vast multitude of
minute cells, that these cells build tissues, that the tissues build
organs, that the organs build the body; but the secret of the man, or
the dog, or even the flea, is beyond its reach. The secret of biology,
that which makes its laws and processes differ so widely from those of
geology or astronomy, is a profound mystery. Science can take living
tissue and make it grow outside of the body from which it came, but it
will only repeat endlessly the first step of life--that of
cell-multiplication; it is like a fire that will burn as long as fuel is
given it and the ashes are removed; but it is entirely purposeless; it
will not build up the organ of which it once formed a part, much less
the whole organized body.
The difference between one man and another does not reside in his
anatomy or physiology, or in the elements of which the brains and bodies
are composed, but in something entirely beyond the reach of experimental
science to disclose. The difference is psychological, or, we may say,
philosophical, and science is none the wiser for it. The mechanics and
the chemistry of a machine are quite sufficient to account for it, plus
the man behind it. To the physics and chemistry of a living body, we are
compelled to add some intangible, unknowable principle or tendency that
physics and chemistry cannot disclose or define. One hesitates to make
such a statement lest he do violence to that oneness, that sameness,
that pervades the universe.
All trees go to the same soil for their ponderable elements, their
ashes, and to the air and the light for their imponderable,--their
carbon and their energy,--but what makes the tree, and makes one tree
differ from another? Has the career of life upon this globe, the
unfolding of the evolutionary process, been accounted for when you have
named all the physical and material elements and processes which it
involves? We take refuge in the phrase "the nature of things," but the
nature of things evidently embraces something not dreamed of in our
science.