the assertion be ventured, that the stone and earth do not act? Do they wish to be undeceived? They have nothing to do but interpose their hand betwixt the earth and the stone; it will then be discovered, that notwithstanding its seeming repose, the stone has power adequate to bruise it; because the hand has not energies sufficient, within itself, to resist effectually both the stone and earth.—Action cannot exist in bodies without re-action. A body that experiences an impulse, an attraction, or a pressure of any kind, if it resists, clearly demonstrates by such resistance that it re-acts; from whence it follows, there is a concealed force, called by these philosophers vis inertia, that displays itself against another force; and this clearly demonstrates, that this inert force is capable of both acting and re-acting. In short, it will be found, on close investigation, that those powers which are called dead, and those which are termed live or moving, are powers of the same kind; which only display themselves after a different manner. Permit us to go a greater distance yet. May we not say, that in those bodies, or masses, of which their whole become evident from appearances to us to be at rest, there is notwithstanding, a continual action, and counter-action, constant efforts, uninterrupted or communicated force, and continued opposition? In short, a nisus, by which the constituting portions of these bodies press one upon another, mutually resisting each other, acting and re-acting incessantly? that this reciprocity of action, this simultaneous re-action, keeps them united, causes their particles to form a mass, a body, and a combination, which, viewed in its whole, has the appearance of complete rest, notwithstanding no one of its particles
