Aphorism 21
§ 21
Aphorism 21 : Now, as it is undeniable that the curative principle in medicines is not in itself perceptible, and as in pure experiments with medicines conducted by the most accurate observers, nothing can be observed that can constitute them medicines or remedies except that power of causing distinct alterations in the state of health of the human body, and particularly in that of the healthy individual, and of exciting in him various definite morbid symptoms; so it follows that when medicines act as remedies, they can only bring their curative property into play by means of this their power of altering man’s state of health by the production of peculiar symptoms; and that, therefore, we have only to rely on the morbid phenomena which the medicines produce in the healthy body as the sole possible revelation of their in-dwelling curative power, in order to learn what disease-producing power, and at the same time what disease-curing power, each individual medicine possesses.
