As despair and security, though contrary to each other, produce the same effects, so absence is observed to have contrary effects, and, in different circumstances, either increases or diminishes our affections. The Duc de la Rochefoucault has very well observed, that absence destroys weak passions, but increases strong; as the wind extinguishes a candle, but blows up a fire. Long absence naturally weakens our idea, and diminishes the passion; but where the idea is so strong and lively as to support itself, the uneasiness, arising from absence, increases the passion, and gives it new force and violence. SECTION V. OF THE EFFECTS OF CUSTOM. But nothing has a greater effect both to increase and diminish our passions, to convert pleasure into pain, and pain into pleasure, than custom and repetition. Custom has two _original_ effects upon the mind, in bestowing a _facility_ in the performance of any action, or the conception of any object, and afterwards a _tendency or inclination_ towards it; and from these we may account for all its other effects, however extraordinary. When the soul applies itself to the performance of any action, or the conception of any object to which it is not accustomed, there is a certain unpliableness in the faculties, and a difficulty of the spirits moving in their new direction. As this difficulty excites the spirits, 'tis the source of wonder, surprise, and of all the emotions which arise from novelty, and is in itself very agreeable, like every thing which enlivens the mind to a moderate degree. But though surprise be agreeable in itself, yet, as it puts the spirits in agitation, it not only augments our agreeable affections, but also our painful, according to the foregoing principle, _that every emotion which precedes or attends a passion is easily converted into it_. Hence, every thing that is new is most affecting, and gives us either more pleasure or pain than what, strictly speaking, naturally belongs to it. When it often returns upon us, the novelty wears off, the passions subside, the hurry of the spirits is over, and we survey the objects with greater tranquillity. By degrees, the repetition produces a facility, which is another very powerful principle of the human mind, and an infallible source of pleasure where the facility goes not beyond a certain degree. And here 'tis remarkable, that the pleasure which arises from a moderate facility has not the same tendency with that which arises from novelty, to augment the painful as well as the agreeable affections. The pleasure of facility does not so much consist in any ferment of the spirits, as in their orderly motion, which will sometimes be so powerful as even to convert pain into pleasure, and give us a relish in time for what at first was most harsh and disagreeable.