In order to be able to observe well, the medical practitioner requires to possess, what is not to be met with among ordinary physicians even in a moderate degree, the capacity and habit of noticing carefully and correctly the phenomena that takes place in natural diseases, as well as those that occur in the morbid states artificially excited by medicines when they are tested upon the healthy hotly, and the ability to describe them in the most appropriate and natural
In order accurately to perceive what is to be observed in patio-nts. we should direct all our thoughts upon the matter we have on hand, come out of ourselves, as it were, and fasten ourselves, so to speak, with all our powers of concentration upon it, in order that nothing that is actually present, that has to do with the subject, and that can be ascertained by all the senses, may escape us.
Poetic fancy, fantastic wit and speculation, must for the time be suspended, and all overstrained reasoning, forced interpretation, and tendency to explain away things must be suppressed. The duty of the observer is only to take notice of the phenomena and their course; his attention should be on the watch, not only that nothing actually present escape his observation, but that also what he observes is understood exactly as it is.
This capability of observing accurately is never quite an innate faculty ; it must be chiefly acquired by practice, by refining and regulating the perceptions of the senses, that is to say, by exercising a severe criticism in regard to the rapid impressions we obtain of external objects, and at the same time the necessary coolness, calmness, and firmness of judgment must be preserved, together with a constant distrust of our own powers of apprehension.
From Nat. Med. Phra, vol. iv, 2d edit, 1825.