Emanuel Swedenborg's Investigations in Natural Science and the Basis for His Statements Concerning the Functions of the Brain

by Martin Ramström

The ›Œconomia Regni Animalis› is chiefly directed to a detailed analysis of the blood, the brain, and finally the soul. In this investigation Swedenborg directed his attention not only to the morphological and physiological aspects of the subject, but also to the embryology of the organs; and he penetrated so deeply into the very essence of development, that, as Professor J. A. Hammar (Uppsala) has pointed out, he succeeded in arriving at a conception on this point, which was considerably better than that of his times. As is well known, during the first part of the eighteenth century the idea was generally prevalent that, when the organism developed from the egg or sperm, it grew forth out of it, much like a flower developes out of the bud, or, in other words, that the different organs existed pre-formed in the egg or sperm and that development consisted only in an extension of its size. Swedenborg expressed himself very decidedly against this ›pre-formation theory›: The development consisted by no means merely in a growth or expansion of the germ, (›seminis extensio›), or of a prototype of the future creature existent in the germ, (›non ... aliqua realis effigies maximi in minimo, seu in aliquo primo typus futuri corporis, qui simpliciter expanditur.› See Œc. R. A. I., No. 249); but there was in the germ a certain formative substance or power, by means of which the various parts of the embryo were developed one after the other, organ after organ. ( ... singula membra successive, seu unum post alterum producuntur ... Œc. R. A. I., No. 247).

It will be seen that Swedenborg has here put forth essentially the same theory as was later presented by Caspar Friedrich Wolff in his well known ›Doctorsdissertation› of the year 1759, i. e., the so called theory of ›epigenesis›.

I shall here also discuss some of the results and conclusions, which Swedenborg arrived at in the ›Œconomia Regni Animalis›, concerning the brain and its function.

As is well known the general principles of the macroscopical anatomy of the brain were known long before Swedenborg’s days; and even its microscopical structure had, half a century before his time, begun to be studied by such men as Leeuwenhoek (1632-1723), Malphigi (1628-1694), and others. For example, it was not only known that the substance of the brain, upon incision, exhibits an outer, greyish layer, the cortex, and an inner, more pure white mass, the medullary substance; but the above-mentioned investigators had also shown that the cortex of the brain consists of a numberless mass of small globular bodies, which are closely surrounded by blood-vessels and are continued in small thread-like extensions, which run into the medullary substance.[28] Now Swedenborg succeeded, as regards these globular bodies, in arriving at the conception that they are the most important components of the cortex and that it is in these bodies that the nerves originate.[29] He called them ›Sphaerulae› or ›Cerebellula›.

Again, as regards the medullary substance, it was already known through the works of Willis (1622-1675), Vieussens (1641-1716), Boerhaave (1668-1738), that it consists, for the most part, of a great mass of finer and coarser nerve-fibres, and that these, through the medulla oblongata,[30] continue down into the spinal cord, and that through the nerves they are in communication with the various parts of the body. The nerves were supposed to contain a lumen, thus being tubular. On the basis of certain clinical experiences concerning the changes which occur in the functions of the soul, when the cortex of the brain is injured, Swedenborg succeeded in drawing the conclusion that the same medullary fibres which are derived from the ›Cerebellula› of the cortex of the brain, continue into the spinal cord and are in connection with the nerves, and that thus an easily transmitted and continuous communication is established between the substance of the cerebral cortex and all the parts of the body, where the nerves are distributed.[31]

Concerning the function of the brain, the old view of Hippocrates that the brain was a gland was still entertained in Swedenborg’s time. The cortical substance served for secreting the ›spiritus animalis›, that is, what the ancients called the ›spirits of life›, and these were collected in the cortex of the brain that they might, when necessary, stream out through the nerves. The medullary substance was, according to the latest conceptions of that day, the origin and source of the soul’s activity, and the ›spiritus animalis› served as the connecting link between the soul and the sense-organs and muscles of the body.

Swedenborg also supposed that such a very easily flowing nervous fluid, ›fluidum spirituosum›, communicated the impressions of the senses and the impulses of motion: but this fluid determined the connection between sense-organs and muscles on the one hand, and the cortex of the brain on the other. It was thus the cerebral cortex! to which the impressions of the senses were carried, and from this the voluntary impulses were sent out to the muscles. The cortex was thus the seat of both the sensory and motor activities of the soul in the body. Œc. R. A. III., No. 133: ›Substantia enim corticalis est ipsum cerebrum, seu sensorium et motorium commune.›[32]

But Swedenborg was not contented with this general idea of the cortex as the seat of the sensations and the will. He also drew conclusions from his previous experience and results regarding the continuous connection between the elements of the cortex and the ends of the nerves distributed in the various parts of the body.

On the basis of this connection he ascribed to the ›Cerebellula› a very important rôle in the activity of the brain. In the first place they received, through the external sense-organs and nerves, impressions from the outer world and worked them over: they were a kind of inner sense-organs.[33] And since the sensory impressions were so richly various as well in kind as in degree, the ›Cerebellula› must also possess various individual qualifications corresponding to these various sensory impressions. They were, at the same time, connected with one another, and so arranged into superior and inferior groups that they could receive and work over the various kinds of sensory impressions.[34]

There were also other groups of grey substance in the interiors of the brain, through which the sensory nerves passed; but all sensory impressions must ultimately be gathered together in the cortex of the brain so as to become conscious perceptions.