A billiard-ball affects my senses, in a particular manner. On account of this, I call it round; and the term round is ever after a mark to me of a portion of the sensations which I derive from it. It affects me in another manner. I call it on that account white, and the term white is to me a mark of this other mode in which it affects me: and in the same manner as I call it white, round, on account of such and such sensations, I call it Moving, on account of certain other sensations, of which the term Moving is to me a perpetual mark.
152 The manner of affecting me on account of which I call it moving, I learn from experience to be peculiarly entitled to my regard. I find that it is a mode of affecting me, which belongs to almost all bodies; and I find that upon this attribute of theirs the greatest part of my interesting sensations depend. I am therefore deeply concerned in the knowledge of motions; and have the strongest inducement to divide them into such classes as may in the highest degree facilitate that knowledge.
Motions are divided in a great variety of ways for a variety of purposes. Sometimes we divide them according to their subjects. Thus, the motion of a bird is one class of motions; the motion of a horse another; so the motion of a serpent, the motion of an arrow, the motion of a wheel. At other times we form classes of motions according to the manner. Thus we have running, flying, rolling, leaping, staggering, throwing, striking, and so on.
Of all the classifications of motions, however, that which deserves the greatest attention is the distinction of them into the motions which originate within the moving body, and those which originate without it. Of the motions which originate within the moving body, the principal are the living motions of animals. We find, also, that of all the motions of animals, those of men are the most important to men. The motions of men are divided into a great number of classes. On account of one set of motions we call a man walking; on account of another sort we call him running; another, writing; another, dancing; another, fencing; another, boxing; another, building; and so on. We have also frequent occasion for a name which shall 153 embrace all these motions of men. For this purpose the word Acting is employed: and the term Action denotes any of the motions, which originate within a man as the moving body. It is no objection to this account of the use of the word action, that it is sometimes employed in cases in which the motion is not the principal object of attention; as in the act of singing, or that of speaking. Here, though it is not the motion, but the effect of the motion, which is the object of attention to the hearer, the act of the singer or speaker is not the less truly a motion.
The word action, when thus invented, and used, is afterwards applied metaphorically to motions which do not originate in the moving body, as when we say the action of a sword; and also to certain processes of the mind, which, as they are accompanied with the feeling we call effort, resembling that which accompanies the voluntary motions, are sometimes classed along with them, and, by an extension of the meaning of the word, receive the name of actions. In this manner, remembering, computing, comparing, even hearing, and seeing, are denominated actions.
2. In applying the term Acting, or the terms expressive of the several kinds of acting, the Time the action is a material circumstance. The grand divisions of time are the Past, the Present, and the Future. There is great utility in a short method of marking these divisions of time in conjunction with the mark of the action. This is effected by the Tenses of Verbs.
3. When the name of an act is applied to an agent the agent is either the person speaking, the person spoken to, or some other person. The word denoting 154 the action is, by what are called the Persons of the verb, made to connote these diversities. Thus amo notes the act, and connotes the person speaking as the actor; amas notes the act, and connotes the person spoken to, as the actor; amat notes the act, and connotes some person, as the actor, who is neither the person speaking, nor the person spoken to.[46]
[46] There is here a fresh instance of the oversight [already] pointed out, that of not including in the function for which general names are required, their employment in Predication. Amo, amas, and amamus, cannot, I conceive, with any propriety be called names of actions, or names at all. They are entire predications. It is one of the properties of the kind of general names called verbs, that they cannot be used except in a Proposition or Predication, and indeed only as the predicate of it: (for the infinitive is not a verb, but the abstract of a verb). What else there is to distinguish verbs from other general names will be more particularly considered [further on].—Ed.
4. When the names of actions are applied to agents, they are applied to one or a greater number. A short method of connoting this grand distinction of numbers is effected by the marks of the Singular and Plural number. Thus amo notes the act, and connotes one actor; amamus notes the act, and connotes more than one actor.
5. In applying the names of actions to the proper subjects of them, there are three Modes of the action, one or other of which is always implied. The first is, when the action has no reference to any thing previously spoken of. The second is, when it has a reference to something previously spoken of. The third is, when it has a reference to some state of the will of 155 the speaker or person spoken of. These diversities of mode are connoted by the Moods of the verb. The Indicative is used when no reference is made to any thing which precedes: the Subjunctive, when a reference is made to something which precedes: and the Optative, and Imperative, when the reference is to the state of the will of the speaker or the person spoken of.