The Epidemics of the Middle Ages by J. F. C. Hecker and John Caius

SYMPATHY. Imitation—compassion—sympathy, these are imperfect designations for a common bond of union among human beings—for an instinct which connects individuals with the general body, which embraces with equal force, reason and folly, good and evil, and diminishes the praise of virtue as well as the criminality of vice. In this impulse there are degrees, but no essential differences, from the first intellectual efforts of the infant mind, which are in a great measure based on imitation, to that morbid condition of the soul in which the sensible impression of a nervous malady fetters the mind, and finds its way, through the eye, directly to the diseased texture, as the electric shock is propagated by contact from body to body. To this instinct of imitation, when it exists in its highest degree, is united a loss of all power over the will, which occurs as soon as the impression on the senses has become firmly established, producing a condition like that of small animals when they are fascinated by the look of a serpent. By this mental bondage, morbid sympathy is clearly and definitely distinguished from all subordinate degrees of this instinct, however closely allied the imitation of a disorder may seem to be to that of a mere folly, of an absurd fashion, of an awkward habit in speech and manner, or even of a confusion of ideas. Even these latter imitations, however, directed as they are to foolish and pernicious objects, place the self-independence of the greater portion of mankind in a very doubtful light, and account for their union into a social whole. Still more nearly allied to morbid sympathy than the imitation of enticing folly, although often with a considerable admixture of the latter, is the diffusion of violent excitements, especially those of a religious or political character, which have so powerfully agitated the nations of ancient and modern times, and which may, after an incipient compliance[324], pass into a total loss of power over the will, and an actual disease of the mind. Far be it from us to attempt to awaken all the various tones of this chord, whose vibrations reveal the profound secrets which lie hid in the inmost recesses of the soul. We might well want powers adequate to so vast an undertaking. Our business here is only with that morbid sympathy, by the aid of which the dancing mania of the middle ages grew into a real epidemic. In order to make this apparent by comparison, it may not be out of place, at the close of this inquiry, to introduce a few striking examples:—