With regard to the function of the brain, SWEDENBORG, in the first place,
made the distinction that the cerebrum regulates the psychic, and the
cerebellum the vegetative functions.
Many different opinions prevailed in SWEDENBORG’s time concerning this
question. Some investigators considered that the vegetative as well as
the psychical functions stood under the direct control of the cerebrum;
others that _the centres of vegetative life were separated from those of
psychic life and had not_, like these, _their place in the cerebrum_.
And SWEDENBORG adopted the latter opinion, primarily for the following
reasons:
1) _Experiments on animals_ had brought to light the fact that
respiration and the action of the heart continued for a time even after
the hemispheres of the cerebrum (in dogs) had been separated from their
connection with the cerebellum and medulla oblongata, indeed, even if the
hemispheres of the cerebrum (in dogs) had been extirpated.[53] He was
also led to the same conclusion by
2) _Certain teratological and pathological anatomical experiences_, which
he had gathered from his studies of books. He advances cases described by
WEPFER, TYSON and RIDLEY, MANGET, KERKRING, MORGAGNI, and others, which
showed that although the cerebrum had occasionally been entirely or in
part missing in foetuses, yet these deformed foetuses could nevertheless
live a shorter or longer time after birth. And in agreement with TULPIUS
he calls attention to the great deformation of the cerebrum in the case
of hydrocephals. In close connection with this he gives accounts (from
VALLISNIERI and others) of extreme cases of petrifications in the brain,
regarding which one must suppose that when the cerebrum gradually lost
its functions and the vegetative vital functions nevertheless continued
for a time, these must then have been regulated by the remaining parts of
the central nervous system, that is, by the cerebellum, medulla oblongata
and the spinal cord. (See Œc. R. A. I., Nos. 573, 574 _et seqq._).
From these experiments and discoveries it was thus evident to SWEDENBORG
that the centres for vegetative life are not to be sought for in the
cerebrum.
As was said, he located them instead in the cerebellum, and the
reason for this seems in brief to have been the following: MANGET and
VIEUSSENS had described a number of experiments on animals which were
said to have proved that after lesions of the cerebellum respiration
and the action of the heart at once ceased.[54] The injuries in these
experiments had evidently extended more deeply than the descriptions
recount, by which the false conclusion in regard to the cerebellum is
explained. It was probably because of such misleading experiments as
these that SWEDENBORG’s highly esteemed contemporary, HERMANN BOERHAAVE,
(1668-1737), held the same opinion that the vegetative vital functions
are regulated by the cerebellum.[55] However, the Englishman THOMAS
WILLIS, (1622-1675), had come nearer the truth, when, in a very guarded
statement, he connected these functions with both the cerebellum and
the medulla oblongata.[56] And when SWEDENBORG chose his position on
the question he seems to have been influenced by both of these authors,
and received the opinion that the cerebellum was the main centre of
vegetative life, making, however, the important addition, that the
medulla oblongata, as for that matter also the spinal cord, are secondary
centres, subordinated to the cerebrum and cerebellum.[57] This addition
was based upon a conclusion which SWEDENBORG had drawn, among other
things, from the teratological and pathologic-anatomical observations and
from comparative anatomy, but there is no occasion for entering into this
more closely in this connection.
After SWEDENBORG had, however, upon the grounds alluded to, separated
the centres for the vegetative life-functions from the cerebrum, there
lay before him the localization of the psychical functions; and, as to
them, SWEDENBORG located the centres of the sensory portion of the soul’s
activity in the cortex of the cerebrum.[58]