Excerpt from The "Summa Theologica" Of St. Thomas Aquinas, Vol. 2: First Part, Second Number Qq. XLIX-LXXXIX After treating of human acts and passions, we now pass on to the consideration of the principles of human acts, and firstly of intrinsic principles, secondly of extrinsic principles. The intrinsic principle is the power and the habit; but as we have treated of the powers in the First Part, it remains for us to consider the habits. And in the first place we shall consider them in general: in the second place we shall con sider Virtues and vices and other like habits, which are the principles of human acts. Concerning habits in general there are four questions to be considered: Firstly, the substance of habits; secondly, their subject; thirdly, the cause of their generation, increase, and corruption; fourthly, how they are distinguished from one another. Under the first head, there are four points of inquiry: (1) Whether habit is a quality P (2) Whether it is a distinct species of quality (3) Whether habit implies an order to an act (4) Of the necessity of habit. 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.