desire, is denominated _an emotion_: when desire is raised, the motion or agitation is denominated _a passion_. A fine face, for example, raiseth in me a pleasant feeling. If this feeling vanish without producing any effect, it is in proper language an emotion. But if such feeling, by reiterated views of the object, become sufficiently strong to raise desire, it is no longer termed an emotion, but a passion. The same holds in all the other passions. The painful feeling raised in a spectator by a slight injury done to a stranger, being accompanied with no desire of revenge, is termed an emotion. But this injury raiseth in the stranger a stronger emotion, which being accompanied with desire of revenge, is a passion. Again, external expressions of distress, produce in the spectator a painful feeling. This feeling is sometimes so slight as to pass away without any effect, in which case it is an emotion. But if the feeling be so strong as to prompt desire of affording relief, it is a passion, and is termed _pity_. Envy is emulation in excess. If the exaltation of a competitor be barely disagreeable, the painful feeling is reckoned an emotion. If it produce desire to depress him, it is reckoned a passion. To prevent mistakes, it must be observed, that desire here is taken in its proper sense, _viz._ that internal impulse which makes us proceed to action. Desire in a lax sense respects also actions and events that depend not on us, as when I desire that my friend may have a son to represent him, or that my country may flourish in arts and sciences. But such internal act is more properly termed a _wish_ than a _desire_. Having distinguished passion from emotion, we proceed to consider passion more at large, with respect especially to its power of producing action. We have daily and constant experience for our authority, that no man ever proceeds to action but through the impulse of some antecedent desire. So well established is this observation, and so deeply rooted in the mind, that we can scarce imagine a different system of action. Even a child will say familiarly, What should make me do this or that when I have no inclination to it? Taking it then for granted, that the existence of action depends on antecedent desire; it follows, that where there is no desire there can be no action. This opens another shining distinction betwixt emotions and passions. The former, being without desire, are in their nature quiescent: the latter, involving desire, have a tendency to action, and always produce action where they meet with no obstruction.