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

by Martin Ramström

ON THE CENTRES OF THE PSYCHICAL FUNCTIONS, ESPECIALLY THE SENSORY CENTRES.

That the sensory activity of the soul has its centres in the cerebrum was in Swedenborg’s time considered quite certain, but it was not so certain as to just what part of the brain it was in which the soul’s activity arose.

It is well known that the philosopher Descartes († 1650) had supposed that the glandula pinealis (pineal gland) was the seat of the soul, and that the conscious perceptions came into being in this gland and in the central ventricle of the brain, the ›third ventricle›, from which the nerves, according to his opinion, took their origin.[59]

Gradually, however, there seems to have been more and more an inclination to attribute this phase of the operation of the soul to the white medullary substance around the ventricles of the brain. And in Swedenborg’s time this opinion seems to have been the usual one. At least the matter is so presented by Hermann Boerhaave, who, as is known, in a high degree had the ear of his contemporaries.[60]

And even Haller, some twenty years after Swedenborg had written his works on the brain, was still of a similar opinion, as is evident from a quotation which I shall here bring forward, in which he emphasizes that neither perceptions nor the impulses to motion arise in the cortex of the cerebrum, but in the medullary substance: ›Non ergo in cerebri cortice sensus sedes erit, aut plena causae muscularis motus origo: eritque utraque in medulla cerebri, & cerebelli.› (Alb. v. Haller: ›Elementa physiologiae›, Lausannae, 1762, Tom. IV., p. 392). But when even Haller would not attribute the soul’s activity to the cortex, what then can have led Swedenborg to such a thought?

In order to clear up this question let us first examine the anatomical literature before Swedenborg’s time. And then we find that the Bartholins had already in a kind of way associated this branch of the soul’s activity with the cerebral cortex, because they supposed that the ›spiritus animalis›, (the ›spirits of life›), was contained in the cortex for the sensory functions, just as it was conserved in the medullary substance for the motor functions.[61]

And Thomas Willis considered that the ›spiritus animalis› was generated in the cerebral cortex, but afterwards underwent proper elaboration and distribution in the medulla of the cerebrum; and that the memory had its seat in the cerebral cortex.[62]

And Malpighi (1628-1694) had expressed the surmise, that the minute cortical elements, so particularly described by him, which correspond to what we now call the nerve-cells of the cortex, were small glands, ›glandulæ›, whose function was to prepare a substance which, conveyed through the nerves, calls forth perceptions.[63]

It had also been shown by the researches of Malpighi that these ›glandulæ› put forth a vessel-like fibre, which continued into the cerebral medulla; and that this medulla for the greater part consisted of such fibres or vessels.[64]

In how far these structures were ›fibres› or ›vessels›, and whether they proceeded from (›oriuntur›) or terminated in (›desinunt›) the small cortical elements, Malpighi leaves undecided. And when Boerhaave afterwards in his lectures on the brain describes these structures, he still depicts them as the finest tiny canals, which take up the ›spiritus animalis›, pressed into them from the cortex, and transport it down to the medulla oblongata, whence it is afterwards, by means of the nerves, distributed to the different parts of the body. This ›spiritus› Boerhaave describes as elaborated in the cortex, ›fabrica mirifica corticis praeparatus›.[65]

These observations and surmises have evidently exercised a great influence upon Swedenborg’s conception of the function of the cerebral cortex; but they alone could impossibly have aided him in reaching the enlightened standpoint at which he arrived. No, the most determining and decisive factor for him in this question evidently was a great mass of clinical and pathological observations which he had collected and synthesized, namely, symptoms of disturbances of consciousness and sensibility, which had been exhibited by such patients, who, as was shown by post mortem examination, had been injured in the cerebral cortex. And I shall later refer to some of these cases in connection with the consideration of the brain’s motor functions, because these patients nearly always also exhibited motor disturbances.

But even here I may quote some of Swedenborg’s own words, which will show what importance he attached to these testimonies: ›It is the cerebrum or the cortical substance in which the soul disposes and unfolds its purest and most simple organic forms of activity, and what the cerebrum is, appears from a change of the faculties in some diseases, as in apoplexy, epilepsy, paralysis, etc., likewise in many morbid states of the animal mind in a cerebrum wounded by various accidents;› (›The Brain›, No. 86).

And in another place he says: ›If the cerebrum is either inflamed or obstructed, or flaccid, or injured otherwise, the intellectual faculty is unsettled; as in paralysis, melancholy, in cases of delirium, in atrophy, apoplexy, in fevers, and other diseases; nay, the determination of the will also is similarly affected. For each single cortical substance contributes its share to this intellectory, that is, to this organ of the understanding, etc.› (›The Brain›, No. 104, r).

All these observations concerning the consequences of injury to the cerebral cortex—and the above-mentioned discoveries regarding the structure of the cerebral substance and the hypotheses concerning the relation of the cerebral cortex and cortical elements to the ›spiritus animalis› and the perceptions,—these clinical and anatomical experiences taken together seem to have led Swedenborg to the conviction that the activity of the soul and not least that just now in question, the sensory, had its seat in the cortex of the cerebrum.

He now enters into a detailed analysis of the course of the sensory nerves as far as they are able to be demonstrated (›in ipsius oculi luce›), and he thus follows the optic nerves to the optic thalami, and thence their radiation towards the cerebral cortex, the olfactory nerves to the corpora striata or the medulla of the centrum ovale and from there out towards its cortical surroundings, the auditory nerves to the medulla oblongata and thence up toward the cortex of the cerebrum, (›versus supremum corticem›), and in the same manner he follows the nerves of taste and touch. (See Œc. R. A. II., No. 192; and III., No. 66). He cannot now follow further the particular fibres through the medulla all the way to the cortex, of whose importance for consciousness and sensibility he became convinced through the clinical experiences, but here he must suppose a connection, and he says: ›these effects (conscious perceptions) could never be produced ... unless in every quarter there were a mutual connection and perpetual communication of the cortical substance with the medullary, as regards the fibrils ...›, (as well as a special arrangement of the cortical elements and special qualifications in them, of which more will be said later).[66]

From all this it is clear, that it was probably through a combination of clinical and anatomical experiences that Swedenborg secured the premises for his conclusions that the centre of the soul’s sensory activity is in the cortex of the cerebrum.