It hath always been reckoned difficult to account for the extreme pleasure that follows a cessation of bodily pain; as when one is relieved from the rack, or from a violent fit of the stone. What is said, explains this difficulty in the easiest and simplest manner. Cessation of bodily pain is not of itself a pleasure; for a _non-ens_ or a negative can neither give pleasure nor pain. But man is so framed by nature as to rejoice when he is eased of pain, as well as to be sorrowful when deprived of any good. This branch of our constitution, is chiefly the cause of the pleasure. The gratification of desire comes in as an accessory cause; and contrast joins its force, by increasing the sense of our present happiness. In the case of an acute pain, a peculiar circumstance contributes its part. The brisk circulation of the animal spirits occasioned by acute pain, continues after the pain is vanished, and produceth a very pleasant feeling. Sickness hath not that effect, because it is always attended with a depression of spirits. Hence it is, that the gradual diminution of acute pain, occasions a mixt emotion, partly pleasant, partly painful. The partial diminution produceth joy in proportion; but the remaining pain balanceth our joy. This mixt feeling, however, hath no long endurance. For the joy that ariseth upon the diminution of pain, soon vanisheth; and leaveth in the undisturbed possession, that degree of pain which remains. What is above observed about bodily pain, is equally applicable to the distresses of the mind; and accordingly it is a common artifice, to prepare us for the reception of good news by alarming our fears. SECT. III. _Sympathetic emotion of virtue, and its cause._