Before proceeding to suggest some means by which to increase the
stability of the national health through the agency of family life, it
will be advantageous to recall the advice given to students of any form
of life by Professor Arthur Thomson:--that they should, before
attempting to form conclusions as to its nature, submit its constitution
to analysis, with the assistance of what he described as the biological
prism. This, he says, will throw light on the inherited nature of the
creature--the capital, so to say, with which it is endowed at birth. It
will illuminate the functional nature of its parts, and will reveal what
it does in the course of its ceaseless activities--nervous, muscular and
organic. Further, the prismatic rays will render visible the results of
some of the influences dependent upon the environment with which it is
surrounded, which play upon it before and after birth. Unfortunately
these rays, when directed to human nature, cannot penetrate so deeply
nor divulge so clearly the secrets of this the highest and most complex
form of life, as they do when directed to its simpler manifestations.
All ordinary difficulties are enhanced by our human capacity for racial
admixture and the creation of an artificial environment.
This much, however, is clearly revealed by a partial analysis. Human
beings, in common with all life, are distinguished by the power of
movement, and are sensitive to many forms of external stimulus:--heat,
cold, electricity, or pressure. They pass their lives in rhythmic
alternations of activity and repose; they breathe; they absorb food to
supply energy and to maintain unimpaired the substance of their bodies;
they excrete waste products. They share with plants and animals an
intrinsic tendency to continue their growth for a certain period and up
to a definite amount, while, at the close of the most pronounced period
of growth, ability to transmit life absorbs the energy hitherto utilised
for personal development, by which means the perpetuation of a species
is secured. Research shows, also without possibility of question, that
certain similar characteristics distinguish the mechanism of every type
of animal life; though the machinery be in some cases of the simplest,
in others highly complex. Thus have been revealed many secrets of man's
physical nature; as, for instance, the knowledge that, in the earliest
stages of their existence, higher forms of life recapitulate more or
less imperfectly certain far-off ancestral phases of development, of
which living specimens are still to be found on the lower branches of
humanity's huge genealogical tree. By means also of the close and
detailed observation of these lowlier organisms a clearer conception
has been formed of the intricacies of growth and the prolonged process
of development in mankind. Just how human beings have come to be what
they are, mentally and morally as well as physically, is a still
unsolved problem. There are, of course, many missing chapters in the
long story of life, though so far no contradictions have been detected
in its arguments. The sad side of this biological lore exists in the now
ascertained fact that the highest intellectual and moral powers, those
last to develop, are the first to suffer arrest or to die away when the
organism is subjected to premature exhaustion or to precocious
responsibility. Predisposing causes are found in disease, dissipation,
or defective nurture.
Another of the more important lessons to be learnt from the pages of
this book of life's history is the conservative influence of the law of
inherited nature; a law which makes for the preservation of racial types
by suppressing wide deviations from the normal. A familiar illustration
of this may be found in the fact that the children of parents of great
height or of very short stature usually revert to the average of the
race. The significance of this genetic relation in maintaining an
efficient people was unrecognised until quite recent times, and though
valuable evidence is accumulating on the descent of hereditary character
in mankind, no definite conclusions have yet been reached on the
_intensity_ of the transmission of qualities. It is, of course, a
subject of intense complexity, the full discussion of which is here
impossible. In the interests of future generations it is, however, to
be wished that more thought were given to the conclusions it is
allowable to draw. "If," for instance, says a recent writer, "instead of
allowing the race to mate at random we selected both parents for some
one quality, we could raise the intensity of inheritance and establish
gradually, by continued selection, a strain in which the quality reached
a value much higher than the average in the original mixed race...."[99]
Thus could a race be strengthened for life's calls, or, on the contrary,
until and unless the people are awakened to the existence and bearing on
their national security of such fundamental hygienic influences, it can
be emasculated. No such selection is likely ever to dominate human
marriages, but an appreciation of these and similar facts is fundamental
to national progress; and in time the dissemination of such knowledge
will be considered a parental duty, the more urgent since the resources
of civilisation and ill-regulated sympathy have combined to brush aside
the sterner laws of nature, so that the deteriorated threaten to become
the chief progenitors of the next generation.
During the process of studying the abundant evidence of life's progress
from the simple to the complex, it becomes also apparent that it is
affected by forces other than heredity. Recognition of the ever-present
influence of these potent but often disregarded forces makes for
harmonious living, whereas their neglect is associated with heavy
penalties. I refer to the capacity for individual variation from the
racial type; to the modification of each individual by his or her
surroundings; and to the personal predisposition, technically described
as diathesis, which influences the reaction made to every form of
stimulus. Of these three forces, the first is the result of an inborn
tendency to deviate from the ancestral type; an orderly process with a
definite intention, by no means a mere chance fluctuation. This
certainly makes for progress as well as for interest in life, though it
enhances the difficulties of education, because it demands the
adaptation of conditions to each individual's requirements. The second,
the law of modification, takes into account the influence of environment
upon inherited nature; the effects of climate, and food, for example, or
of forms of occupation. Predisposition is, of course, a personal
quality--a factor of primary importance in our susceptibility to or
power to resist disease or in our capacity to withstand adverse
conditions. This property is responsible for the greater or less degree
of adaptability to new conditions possessed by each of us, and is
concerned with our power to live in tune or at discord with our
surroundings.
Another biological law, that of periodicity,[100] or of rhythmic
alternations of activity and rest, has hitherto often suffered among
human beings more in the breach than in the observance of its tenets;
though unquestionably conformity to its requirements makes for health
and stability. Throughout nature habits of rhythmic, organic activity
are too familiar to attract attention. Of these, the periodic return of
the seasons, for instance, or the daily tides, the flowering of plants
and the ripening of fruit, the migrations of birds and the hibernation
of certain insects and animals, are obvious examples. These rhythms have
been proved by experience to be advantageous in the world. They make for
efficiency and economise energy, and, from their high degree of
development in man's nature, it may be fairly assumed that to him their
observance is of great consequence. Many of them are beyond his control;
such, for example, as the diurnal variations of his body temperature,
the beating of the heart, the call of hunger, or the rhythm of growth.
Others he can observe or abuse according to his pleasure; sleep, for
instance, or the rhythm of work, or the daily discharge from his body of
its waste products.[101] It is the work of hygiene to demonstrate how to
combine obedience to all these laws with the demands of modern
existence, and it is the duty of man to conform reasonably to modes of
life based on these demonstrations. More especially does responsibility
for the establishment of certain rhythms, such as sleep, devolve upon
the organiser of a child's early life.