Monism as Connecting Religion and Science | Page 8

and fertilised

by the theory of descent.[14]
Just as the natural doctrine of development on a monistic basis has
cleared up and elucidated the whole field of natural phenomena in their
physical aspect, it has also modified that of the phenomena of mind,
which is inseparably connected with the other. Our human body has
been built up slowly and by degrees from a long series of vertebrate
ancestors, and this is also true of our soul; as a function of our brain it
has gradually been developed in reciprocal action and re-action with
this its bodily organ. What we briefly designate as the "human soul," is
only the sum of our feeling, willing, and thinking--the sum of those
physiological functions whose elementary organs are constituted by the
microscopic ganglion-cells of our brain. Comparative anatomy and
ontogeny show us how the wonderful structure of this last, the organ of
our human soul, has in the course of millions of years been gradually
built up from the brains of higher and lower vertebrates. Comparative
psychology teaches us how, hand in hand therewith, the soul itself, as
function of the brain, has been developed. The last-named science
teaches us also that a primitive form of soul-activity is already present
even in the lowest animals, the single-celled primitive animals,
Infusoria and Rhizopoda. Every scientific man who has long observed
the life-activity of these single-celled Protista, is positively convinced
that they also possess a soul; that this "cell-soul" also consists of a sum
of sensations, perceptions, and volitions; the feeling, thinking, and
willing of our human soul differ from these only in degree. In like
manner there is present in the egg-cell (as potential energy) a hereditary
cell-soul, out of which man, like every other animal, is developed.[15]
The first task of a truly scientific psychology will therefore be, not, as
hitherto, idle speculation about an independent immaterial
soul-existence and its puzzling temporary connection with the animal
body, but rather the comparative investigation of the organs of the soul
and the experimental examination of their psychical functions. For
scientific psychology is a part of physiology, the doctrine of the
functions and the life-activities of organisms. The psychology and
psychiatry of the future, like the physiology and pathology of to-day,
must take the form of a cellular study, and in the first instance
investigate the soul-functions of the cells. Max Verworn, in his fine
_Psycho-physiological Protistastudies_, has lately shown us what

important disclosures such a cellular psychology can make, even in
dealing with the lowest grades of organic life, in the single-celled
Protista (especially Rhizopoda and Infusoria).
These same main divisions of soul-activity, which are to be met with in
the single-celled organism,--the phenomena of irritability, sensation,
and motion,--can be shown to exist in all multicellular organisms as
functions of the cells of which their bodies are composed. In the lowest
Metazoa, the invertebrate sponges and polyps, there are, just as in
plants, no special soul-organs developed, and all the cells of the body
participate more or less in the "soul-life." It is only in the higher
animals that the soul-life is found to be localised and connected with
special organs. As a consequence of division of labour, there have here
been developed various sense-organs as organs of specific sensibility,
muscles as organs of motion and volition, nerve-centres or ganglia as
central co-ordinating and regulating organs. In the most highly
developed families of the animal kingdom, these last come more and
more into the foreground as independent soul-organs. In
correspondence with the extraordinarily complicated structure of their
central nervous system (the brain with its wonderful complex of
ganglion-cells and nerve-fibres), the many-sided activity of such
animals attains a wonderful degree of development.
It is only in these most highly-developed groups of the animal kingdom
that we can with certainty establish the existence of those most perfect
operations of the central nervous system, which we designate as
consciousness. As we know, it is precisely this highest brain-function
that still continues to be looked upon as a completely enigmatical
phenomenon, and as the best proof for the immaterial existence of an
immortal soul. It is usual at the same time to appeal to Du
Bois-Reymond's well-known "Ignorabimus address on the Boundaries
of Natural Knowledge" (1872). It was by a peculiar irony of fate that
the famous lecturer of the Berlin Academy of Science, in this
much-discussed address of twenty years ago, should be representing
consciousness as an incomprehensible marvel, and as presenting an
insuperable barrier to further advances of knowledge, at the very
moment that David Friedrich Strauss, the greatest theologian of our
century, was showing it to be the opposite. The clear-sighted author of
The Old Faith and the New had already clearly perceived that the

soul-activities of man, and therefore also his consciousness, as
functions of the central nervous