whose province should be to guard against the causes of disease, to eliminate them if possible when still present, to order all the conditions of the patient so as to favor the efforts of the system to right itself, and to give those predictions of the course of disease which only experience can warrant, and which in so many cases relieve the exaggerated fears of sufferers and their friends, or warn them in season of impending danger.  Great as the loss would be if certain active remedies could no longer be obtained, it would leave the medical profession the most essential part of it’s duties, and all, and more than all, its present share of honors; for it would be the death-blow to charlatanism, which depends for its success almost entirely on drugs, or at least on a nomenclature that suggests them.

There is no offence, then, or danger in expressing the opinion, that, after all which has been said, the community is still overdosed:  The best proof of it is, that “no families take so little medicine as those of doctors, except those of apothecaries, and that old practitioners are more sparing of active medicines than younger ones.” [Dr. James Jackson has kindly permitted me to make the following extract from a letter just received by him from Sir James Clark, and dated May 26, 1860:  “As a physician advances in age, he generally, I think, places less confidence in the ordinary medical treatment than he did, not only during his early, but even his middle period of life.”] The conclusion from these facts is one which the least promising of Dr. Howe’s pupils in the mental department could hardly help drawing.

Part of the blame of over-medication must, I fear, rest with the profession, for yielding to the tendency to self-delusion, which seems inseparable from the practice of the art of healing.  I need only touch on the common modes of misunderstanding or misapplying the evidence of nature.

First, there is the natural incapacity for sound observation, which is like a faulty ear in music.  We see this in many persons who know a good deal about books, but who are not sharp-sighted enough to buy a horse or deal with human diseases.

Secondly, there is in some persons a singular inability to weigh the value of testimony; of which, I think, from a pretty careful examination of his books, Hahnemann affords the best specimen outside the walls of Bedlam.

The inveterate logical errors to which physicians have always been subject are chiefly these: 

The mode of inference per enumerationem simplicem, in scholastic phrase; that is, counting only their favorable cases.  This is the old trick illustrated in Lord Bacon’s story of the gifts of the shipwrecked people, hung up in the temple.—­Behold! they vowed these gifts to the altar, and the gods saved them.  Ay, said a doubting bystander, but how many made vows of gifts and were shipwrecked notwithstanding?  The numerical system is the best corrective of this and similar errors.  The arguments commonly brought against its application to all matters of medical observation, treatment included, seem to apply rather to the tabulation of facts ill observed, or improperly classified, than to the method itself.