Excerpt from The Natural Theology of the Doctrine of the ForcesThe great change which has passed over the philosophy of physics in our day, relates to the doctrine of the forces, and scientific teach ing now affirms the correlation, or convertibility, of them all.The idea of force, which lies at the basis of this View, is yet far from being clearly defined in the conception of the physical philosopher. It is vaguely conceived as something lying back of phenomena, to which the latter are to be referred as their ground or cause. All the varied phenomena of the physical world, and, indeed, of the physical universe, are attributed, not as recently they were to imponderable ¿uids or agents, but to motions of the masses, or the particles, of matter, motions which are themselves due to the action of certain impelling forces. The chief interest which attaches to the subject arises from the apparently successful attempts that have been made to convert one of these forces into another, and thus to arrive at a generalization which will admit of our grouping them together, as forms or manifestations of a single force.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.