Moral Philosophy is the science of the moral order, or of the right and wrong of human acts. It is called Ethics from the Greek word êthê which, like the Latin word mores, signifies morals. Since its object is not merely speculative knowledge, but the true direction of human acts, Ethics is also styled Practical Philosophy. To explain the object of Moral Philosophy, which we have declared to be the true direction of human acts, we shall treat in Book I. of the direction of human acts in general; in Book II., of the special duties and rights of men viewed as individuals; and, in Book III., of the rights and duties of men viewed as members of society