Excerpt from A Dictionary of Science: Comprising Astronomy, Chemistry, Dynamics, Electricity, Heat, Hydrodynamics, Hydrostatics, Light, Magnetism, Mechanics, Meteorology, Pneumatics, Sound, and Statics; Preceded by an Essay on the History of the Physical Sciences Metaphysics and Physics have always been more or less connected, and at an early period, the distinction between them was less obvious than it has since been. In the first ages of philosophy, the two were closely blended; in a later age they were entirely dissevered; later again there was a slight union of the two at certain points of contact which had not before appeared. There was undoubtedly a crude form of physical philosophy coeval with the rise of mental philosophy; but the former can scarcely be said to have existed for more than two centuries. Compared with the philosophy of mind, the philosophy of matter is essentially modern. There were vast and exhaustive treatises on the one, before the other had received any development whatsoever. In the Platonic philosophy, we find the grandest development of a pure philosophy of mind, but at this time, and twenty centuries later, there was no physical system which could pretend to any degree of completeness. About the Publisher Forgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.com This 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.