in a general sense, implies nearly the same thing with Act. Grammarians, however, observe some distinction between *action* and *act*; the former being generally restricted to the common or ordinary transactions, whereas the latter is used to express those which are remarkable. Thus, we say it is a good *action* to comfort the unhappy; it is a generous *act* to deprive ourselves of what is necessary for their sake.

in Commerce, is a term used abroad for a certain part or share of a public company's capital stock. Thus, if a company has 400,000 livres capital stock, this may be divided into 400 actions, each consisting of 1000 livres.

in Mechanics, implies either the effort which a body or power makes against another body or power, or the effect itself of that effort.

All power is nothing more than a body actually in motion, or which tends to move itself; that is, a body which would move itself if nothing opposed it. The action therefore of a body is rendered evident to us by its motion only; and consequently we must not fix any other idea to the word motion. The famous question relating to *vis viva* and *vis mortua* owes its existence, in all probability, to an inadequate idea of the word action; for had Leibnitz and his followers observed that the only precise and distinct idea we can give to the word force or action reduces it to its effect, that is, to the motion it actually produces or tends to produce, they would never have made that curious distinction.

**Quantity of Action**, a name given by M. de Maupertuis, in the Memoirs of the Parisian Academy of Sciences for 1744, and those of Berlin for 1746, to the product of the mass of a body by the space which it runs through, and by its celerity. He lays it down as a general law, that "in the changes made in the state of a body, the quantity of action necessary to produce such change is the least possible." This principle he applies to the investigation of the laws of refraction, of equilibrium, &c. and even to the ways of acting employed by the Supreme Being. In this manner M. de Maupertuis attempts to connect the metaphysics of final causes with the fundamental truths of mechanics.

in Law, is a demand made before a judge for obtaining what we are legally entitled to demand, and is more commonly known by the name of *law-suit* or *process*.

in Oratory, is the outward deportment of the orator, or the accommodation of his countenance, voice, and gesture, to the subject of which he is treating.

in Painting and Sculpture, is the attitude or position of the several parts of the face, body, and limbs, of such figures as are represented, and whereby they seem to be really actuated by passions. Thus, we say, the action of such a figure finely expresses the passions with which it is agitated; we also use the same expression with regard to animals.

in Physiology, is applied to the functions of the body, whether vital, animal, or natural.—The *vital* functions, or actions, are those which are absolutely necessary to life, and without which there is no life; as the action of the heart, lungs, and arteries.—The *natural* functions are those which are instrumental in repairing the several losses which the body sustains; for life is destructive of itself, its very offices occasioning a perpetual waste. The manucaction of food, the deglutition and digestion thereof, also the separation and distribution of the chyle and excrementitious parts, &c. are under the head of natural functions, as by these our aliment is converted into our nature. They are necessary to the continuance of our bodies.—The *animal* functions are those which, though not absolutely essential to life, are distinctive of animal existence, such as sensation, and voluntary motion.

in Poetry, the same with subject or fable. Critics generally distinguish two kinds, the principal and the incidental. The principal action is what is generally called the *fable*, and the incidental an *episode*.