Agrippa.—The writings of Cornelius Agrippa, a contemporary of Paracelsus, and, like him, a student of alchemy and of the secrets of nature, contain corresponding passages which serve to show how much of interest there was in mental influence during the Renaissance. All of these men were, of course, a little outside of the ordinary medical tradition, intent on getting to realities, not being satisfied either with words or assumptions, refusing to accept many thing that the physicians of their time completely credited. Agrippa in a characteristic passage said:
Our mind doth effect divers things by faith (which is a firm adhesion, a fixed intention, and a vehement application of the worker or receiver) in him that coöperates in anything, and gives power to the work which we intend to do. So that there is made in us, as it were, the image of the virtue to be received, and the thing to be done in us, or by us. We must, therefore, in every work and application of things, affect vehemently, imagine, hope and believe strongly, for that will be a great help.
Van Helmont.—At the end of the sixteenth century Van Helmont, who carried on the work in pharmaceutics begun by Paracelsus, and to whom we owe the discovery of a number of substances commonly used, as well as the invention of the word "gas," was a thorough believer in the influence of mind over body and, indeed, in the existence in human beings of storehouses [{16}] of latent energy ordinarily unemployed, but that might under special circumstances be tapped to produce wonderful effects. Indeed, some passages remind us of Prof. James' expressions in his discussion of the law of human energy. Van Helmont said:
All magical power lies dormant in man, and requires to be excited. (Compare Prof. James's "Law of Mental Energy" in the chapter on Mental Influence). This (need for excitation) is particularly the case if the subject upon whom we wish to operate is not in the most favorable disposition; if his internal imagination does not abandon itself entirely to the impression we wish to make upon him; or if he towards whom the action is directed possesses more energy than he who operates. But when the patient is well disposed or weak, he readily yields to the magnetic influence of him who operates upon him through the medium of his imagination. In order to operate powerfully, it is necessary to employ some medium; but this medium is nothing unless accompanied by internal action.
Sydenham.—In the more modern period the deliberate use of the influence of the mind on the body is quite as clear. Undoubtedly the greatest of modern physicians, who well deserves the name of the English Hippocrates, is Sydenham. How much Sydenham realized that many of his patients' ailments could only be cured by occupying their minds with other things is seen in his writings. There is a characteristic story told by Dr. Paris in his "Pharmacologia" which illustrates this well and is a striking anticipation of what we are prone to think of as very modern views in these matters:
This great physician, Sydenham, having long attended a gentleman of fortune with little or no advantage, frankly avowed his inability to render him any further service, at the same time adding, that there was a physician of the name of Robertson, at Inverness, who had distinguished himself by the performance of many remarkable cures of the same complaint as that under which his patient labored, and expressing a conviction that, if he applied to him, he would come back cured. This was too encouraging a proposal to be rejected; the gentleman received from Sydenham a statement of his case, with the necessary letter of introduction, and proceeded without delay to the place in question. On arriving at Inverness, and anxiously inquiring for the residence of Dr. Robertson, he found, to his utter dismay and disappointment, that there was no physician of that name, nor ever had been in the memory of any person there. The gentleman returned, vowing eternal hostility to the peace of Sydenham, and on his arrival, at home indignantly expressed his indignation at having been sent on a Journey of so many hundred miles for no purpose. "Well," replied Sydenham, "are you better in health?" "Yes, I am now quite well; but no thanks to you." "No," says Sydenham, "but you may thank Dr. Robertson for curing you. I wished to send you on a journey with some object of interest in view; I knew it would be of service to you: in going, you had Dr. Robertson and his wonderful cures in contemplation; and in returning, you were equally engaged in thinking of scolding me."
Morgagni.—In the century following Sydenham we have a number of examples cited by Morgagni, the father of pathology, in which his recognition of the value of the mind as a curative agent and of the harm that may be done by over-occupation of the mind is set forth at its proper value. Benjamin Ward Richardson in his "Disciples of AEsculapius" [Footnote 2] tells of two incidents in which this phase of Morgagni's very practical application of knowledge to medical practice is exemplified:
[Footnote 2: London, 1901]
In other examples, where the symptoms are due to mental oppression, he pursued a course of treatment that was of soothing nature. A distinguished professor of physic at Bologna happened to discover that his pulse was intermittent, and being extremely anxious about it was incessantly feeling his pulse, to discover that the evil was daily increasing. Morgagni's advice to his patient was to take his finger off his wrist and not to inquire too anxiously about his condition. The advice was followed, and the result was a complete removal of the disturbance.
It is a very singular truth that in describing the action of the nervous system on the circulation Morgagni shows that he was cognizant of the fact that the circulation may be disturbed by two sets of nervous irritations, one inflicted through the pneumogastrics, the other "through those nerves which are subservient to the arteries"—the vaso-motor system which is readily disturbed by the mind. In one patient he observed great perturbations of the pulse in both wrists as the result of mental anxiety. But a day or two later the pulse derangement was confined to the left side altogether. The pulse of the right arm was quite regular, while that of the left arm still showed the inequality. When the mental distress was relieved, this pulse also became equal.