Morgagni cites Sydenham's contemporary, Lancisi, the great Italian physician, as recognizing the influence of the emotions on the heart. Examples of similar convictions as to mental influence in medicine are also found in the works of Morgagni's great contemporaries, Boerhaave and Van Swieten, and the great physicians of the seventeenth and eighteenth centuries were closely imitated in their recognition of the value of the influence of mind over body in medicine by their successors in the profession.
John Hunter.—Wise old John Hunter recognized the influence of the mind on the body very clearly. He said, for instance, "There is not a natural action in the body, whether voluntary or involuntary, that may not be influenced by the peculiar state of mind at the time." He lays it down as a law that "every part of the body sympathizes with the mind, for whatever affects the mind, the body is affected in proportion." He said further, "as a state of the mind is capable of producing a disease, another state of it may affect a cure." He called attention to the fact that the touch of a corpse produced wonderful effects upon the minds of patients. He said, "Even tumors have yielded to the stroke of a dead man's hand." He observes that "while we should naturally expect that diseases connected with the nerves—and those in which their alteration is in the action of parts not in their structure—would be most affected by the imagination, we find that there are other diseases in which they appear to have little connection that are much affected by the state of mind."
German Mind Healing.—In his monograph on "Psychotherapy in Its Scientific Aspects" [Footnote 3] Dr. Berthold Kern calls attention to a forgotten book of the German physician Scheidemantel, published in 1787. Its title was "The Emotions as Remedies." It seems to be very rare since even our Surgeon General's Library has no copy of it. The author treated psychotherapy systematically. He insisted that man was a unit in which body and soul mutually influenced each other. Scheidemantel blamed the moralists for considering the soul exclusively and the physicians for thinking only of the body. He thought that this was a serious mistake for both sides and he seems to have anticipated much of our recent discussion on the influence of the body and [{18}] of things physical generally in what is called crime and various divagations from law. On the other hand, he thought that the influence of the mind on the body was one of the most important elements in therapeutics.
[Footnote 3: "Die Psychische Krankenbehandlung im Ihren Wissenschaftlichen Grundlagen." Berlin 1910.]
Reil, after whom the Island of Reil is named, and who taught us much with regard to brain anatomy, was also interested in the influence of mind on body. He was the professor of anatomy at Berlin in the early part of the nineteenth century and had great influence over the medical science of the time. He insisted on the recognition and development of psychotherapy and hoped to give it a place beside the medical and surgical treatment of human ills. He did much to create a current of thought in German medicine which culminated in Johann Müller's very definite expressions with regard to the power of the mind over the body.
Very probably the most striking expression of the influence of mind upon body is in that wonderful old book, Johann Müller's text-book of physiology, issued in an English edition (London, 1842) under the title "Elements of Physiology." The subject, a favorite study, is set forth very clearly, and evidently from personal knowledge. He recognized that the mind might influence every organ and function of the body. The influence of expectancy he emphasized particularly:
The influence of ideas upon the body gives rise to a very great variety of phenomena which border on the marvelous. It may be stated as a general fact that any state of the body, which is conceived to be approaching and which is expected with perfect confidence and certainty of its occurrence, will be very prone to ensue as the mere result of that idea, if it do not lie without the bounds of possibility. The case mentioned by Pictet, in his observations on nitrous oxide, may be adduced as an illustration of such phenomena. A young lady, Miss B., wished to inspire this intoxicating gas; but in order to test the power of the imagination, common atmospheric air was given to her, instead of the nitrous oxide. She had scarcely taken two or three inspirations of it, when she fell into a state of syncope, which she had never suffered previously; she soon recovered. The influence of the ideas, when they are combined with a state of emotion, generally extends in all directions, affecting the senses, motions and secretions. But even simple ideas, unattended with a disturbed state of the passions, produce most marked organic effects in the body.
With regard to the influence of the mind over the body in the matter of fatigue Müller is especially emphatic. He states just as clearly two generations ago the Law of Reserve Energy as James stated it in recent years. Of course, Müller was far beyond his time in everything, but then men who really think always are, and even Müller's accurate expression only represents what had been in the minds of thinking men in many previous generations. He says:
The idea of our own strength gives added strength to our movements. A person who is confident of effecting anything by muscular efforts, will do it more easily than one not so confident in his own power. The idea that a change is certainly about to take place in the actions of the nervous system, may produce such a change in the nervous energy, that exertions hitherto impossible become possible. This is still more likely to be the case, if the individual is at the time in a state of mental emotion.
Even this necessarily fragmentary and rather disjointed sketch of the main features of psychotherapeutics, as we see them recognized by the great [{19}] physicians of the past, serve to show that mental influence has always been appreciated as an important element in the care of the individual patient.