Excerpt from Introductory Lecture to the Course on the Institutes of Medicine: Delivered in the University of Pennsylvania, October 16th, 1859The great difficulty of medical art and science arises from the number, diversity, and obscurity of its pheno mena. A very slight observation will demonstrate that the phenomena of living beings are very dissimilar, that though each is acting independently yet all occur to a common end. A further observation demonstrates that a large proportion of the phenomena of living organisms are identical with those of the collateral sciences, have a similar origin and are amenable to the same laws.In constructing animal organisms nature has not provided a single organic and vital material for all the tissues and organs, or a single organic form or principle, but has drawn largely on other and exterior aids for her materials, and borrowed, if the term may be used, the forces and phenomena of the exterior world, which our finite intelligence compels us to separate into distinct sciences, though no such distinction exists in nature.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.