Pleasure in unraveling the perplexities of medical practice—in guiding and assisting Nature’s processes when salutary, and in arresting them when not so. Mental management of the sick. Results of practice of the judicious physician gratifying. The physician a hopeful, cheerful man. Gratification of his humanity and benevolence. His attachments. His social enjoyments. His opportunity for exerting a good moral influence. CHAPTER I. UNCERTAINTY OF MEDICINE. The uncertainty of medicine is a common topic in all circles; and yet it is one which is very generally misunderstood, even by the intelligent and reflecting in the community. They mistake as to the nature of this uncertainty, its causes, its practical influence in the treatment of disease, the means which should be resorted to in order to diminish it, and the best methods of guarding against the errors into which it is liable to lead us. These errors are, I may remark, so numerous and so common, and interfere so constantly with the usefulness of the physician among high and low, educated and uneducated, almost equally, that the subject is one of vast practical importance. It is important not only to physicians, but to the people, and to the people especially, for _they_ are the sufferers from the multiform and often fatal injuries, which these errors engender. It will be profitable then to examine the different points to which I have alluded, so that it may be seen how far the science of medicine merits confidence, and by what tests an intelligent and thinking man may distinguish between that which rests upon good and substantial evidence, and that which is uncertain and delusive. This is a distinction which often fails to be made, (as the physician has occasion every day to lament,) by the shrewd and learned, as well as the ignorant and unwary; and the deductions of a rational and careful experience are continually confounded with the false assumptions, and plausible fallacies of the mere pretender, and the fanciful vagaries of the enthusiast. So far as my remarks will enable the reader to make the distinction to which I have referred, just so far will my object be accomplished.