l88 THE HISTORY OF BIOLOGY 



But while Hoffmann leaves the latter to the metaphysicians, Swedenborg 

 becomes involved in speculations upon it; he holds that it likewise consists 

 of a fine material substance, which leaves the body at death and continues 

 to live in space; during life it receives mental impressions from the animus 

 and forms them into knowledge. But what interests him most deeply is the 

 question why knowledge is limited; like van Helmont he concludes that this 

 is due to the Fall, for before the Fall Adam was omniscient, and it now be- 

 came Swedenborg's aim to acquire this omniscience. He mainly sought to 

 gain it by studying the function of the brain and its relation to the life of 

 the soul. 



Swedenborg's investigations of the brain really constitute the principal 

 part of his activities as a natural scientist. In this field he succeeded, by 

 brilliant comparison of conclusions drawn from the results of clinical post- 

 mortem examinations and from contemporary anatomical works — mainly 

 Malpighi's and Vieussens's researches referred to above • — in creating a 

 theory to explain the function of the central nervous system, which is far 

 superior to any that the anatomical specialists of his time were capable of 

 forming. Thus he localized the functions of the soul entirely in the cortex of 

 the great brain and was of the opinion that the corpuscula of the latter (the 

 pyramid-cells) discovered by Malpighi are connected by means of threads 

 with the various parts of the body and with one another, so that definite parts 

 of the body and definite parts of the cerebral cortex are conjoined to one 

 another and form the substructure for the functions of the soul ; it is through 

 this apparatus that the sensations are put into motion. This theory of the 

 brain, the value of which has been appreciated only in modern times, was, 

 however, made the basis for the most fantastic speculations on the soul, 

 which Swedenborg now believes to consist of a "fluidmn spirituostim,'' a 

 substance of exceptional fineness and directly derived from the eternal light. 

 It is impossible, owing to the existence of sin, for man during his earthly 

 life to come into contact with this supreme soul-substance, '' anima,'' which 

 possesses entirely ideal qualities, but he must be content w4th such lower 

 experiences as his mens and animus give him through the senses. Swedenborg 

 himself sought by way of desperate spiritual struggles to acquire that ideal 

 knowledge which man, in his view, had inaccessibly preserved within him, 

 but when he thought that he had attained his object after the vision men- 

 tioned above, his victory led merely to an initiation into the secrets of the 

 spiritual world, which has certainly conduced to the edification of the few 

 members of the Church he founded and of the far more numerous followers 

 of spiritualism, but which has proved absolutely useless to science and to 

 humanity at large, and which besides was the cause of the really splendid 

 contributions he made in the field of natural research being considerably 

 underestimated for a long time afterwards. It has been left to our own time 



