Medical Inquiries and Observations, Vol. 2 / The Second Edition, Revised and Enlarged by the Author

BY BENJAMIN RUSH, M. D. PROFESSOR OF THE INSTITUTES AND PRACTICE OF MEDICINE, AND OF CLINICAL PRACTICE, IN THE UNIVERSITY OF PENNSYLVANIA. IN FOUR VOLUMES. VOL. II. THE SECOND EDITION, REVISED AND ENLARGED BY THE AUTHOR. PHILADELPHIA, PUBLISHED BY J. CONRAD & CO. CHESNUT-STREET, PHILADELPHIA; M. & J. CONRAD & CO. MARKET-STREET, BALTIMORE; RAPIN, CONRAD, & CO. WASHINGTON; SOMERVELL & CONRAD, PETERSBURG; AND BONSAL, CONRAD, & CO. NORFOLK. PRINTED BY T. & G. PALMER, 116, HIGH-STREET. 1805.



GENTLEMEN,
It was for the laudable purpose of exciting a spirit of emulation and inquiry, among the members of our body, that the founders of our society instituted an annual oration. The task of preparing, and delivering this exercise, hath devolved, once more, upon me. I have submitted to it, not because I thought myself capable of fulfilling your intentions, but because I wished, by a testimony of my obedience to your requests, to atone for my long absence from the temple of science.
The subject upon which I am to have the honour of addressing you this evening is on the influence of physical causes upon the moral faculty.

It has long been a question among meta physicians, whether the conscience be seated in the will or in the understanding. The controversy can only be settled by admitting the will to be the seat of the moral faculty, and the understanding to be the seat of the conscience. The mysterious nature of the union of those two moral principles with the will and understanding, is a subject foreign to the business of the present inquiry.
As I consider virtue and vice to consist in action , and not in opinion, and as this action has its seat in the will , and not in the conscience, I shall confine my inquiries chiefly to the influence of physical causes upon that moral power of the mind, which is connected with volition, although many of these causes act likewise upon the conscience, as I shall show hereafter. The state of the moral faculty is visible in actions, which affect the well-being of society. The state of the conscience is invisible, and therefore removed beyond our investigation.