isconnected medley of images and desires.
Even artificial interference with, and changes in the bodily organisation
react upon the mind. The removal of the thyroid gland may result in
idiocy. Castration not only prevents the "breaking" of the voice in the
Sistine choristers, it damps the fires of life to dulness, and makes of
the impetuous Abelard a comfortable discursive father-confessor. The mind
is bound up almost piece by piece with its material basis. Through the
"localisation" of psychic processes in the particular parts of the brain,
naturalism has enormously strengthened the impression that existed even
among the ancients, that sensation and imagination are nothing more than,
let us say, what the note is to a tightly stretched string. Cerebrum and
cerebellum are regarded as the seats of different psychic processes. The
secret of the higher processes is believed to be hidden in the grey matter
of the cortex of the cerebrum. We seek and find in the various lobes and
convolutions of the brain the "centres" for the different capacities, the
power of sight, of smell, of moving the arms, of moving the legs, of
associating ideas, of co-ordinated speech, and so on. When brain and
spinal cord are injured or removed piece by piece from a pigeon or a frog,
it seems as if the "soul" were eliminated piece by piece,--the capacity for
spontaneous free co-ordination, for voluntary action, for the various
sense-impressions, and so on from the higher to the lower. It has even
been maintained that the different feelings and perceptions which are
gradually acquired can be apportioned among the individual cells of the
brain in which they are localised, and the thought-processes, the
associations of percepts, the origin of consecutive ideas, the rapid and
easy recalling of memory-images, and the process of voluntary control, of
instincts, can be explained as due to the "gradual laying down of
nerve-paths" between the different centres and areas of localisation in
the brain. All this seems to refute utterly the old belief in the unity
and personality of the soul. It is different in youth and in age, and
indeed varies continually. It is the ever-varied harmony of the notes of
all the strings which are represented by the fibres and ganglion-cells of
the nerve-substance. It apparently can not only be completely confused and
brought to disharmony, but it may be halved and divided. An almost
terrifying impression was produced when Trembley in