| This happens, among other cases, whenever any object excites contrary passions. |
| For it is observable that an opposition of passions commonly causes a new emotion in the spirits, and produces more disorder, than the concurrence of any two affections of equal force. |
| This new emotion is easily converted into the predominant passion, and encreases its violence, beyond the pitch it would have arrived at had it met with no opposition. |
| Hence we naturally desire what is forbid, and take a pleasure in performing actions, merely because they are unlawful. |
| The notion of duty, when opposite to the passions, is seldom able to overcome them; and when it fails of that effect, is apt rather to encrease them, by producing an opposition in our motives and principles. |
| The same effect follows whether the opposition arises from internal motives or external obstacles. |
| The passion commonly acquires new force and violence in both cases. |
| The efforts, which the mind makes to surmount the obstacle, excite the spirits and inliven the passion. |
| Uncertainty has the same influence as opposition. |
| The agitation of the thought; the quick turns it makes from one view to another; the variety of passions, which succeed each other, according to the different views; All these produce an agitation in the mind, and transfuse themselves into the predominant passion. |
| There is not in my opinion any other natural cause, why security diminishes the passions, than because it removes that uncertainty, which encreases them. |
| The mind, when left to itself, immediately languishes; and in order to preserve its ardour, must be every moment supported by a new flow of passion. |
| For the same reason, despair, though contrary to security, has a like influence. |
| It is certain nothing more powerfully animates any affection, than to conceal some part of its object by throwing it into a kind of shade, which at the same time that it chews enough to pre-possess us in favour of the object, leaves still some work for the imagination. |
| Besides that obscurity is always attended with a kind of uncertainty; the effort, which the fancy makes to compleat the idea, rouzes the spirits, and gives an additional force to the passion. |
| 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 encreases or diminishes our affections. |
| The Duc de La Rochefoucault has very well observed, that absence destroys weak passions, but encreases 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, encreases the passion and gives it new force and violence. |
| SECT. V OF THE EFFECTS OF CUSTOM |
| But nothing has a greater effect both to encrease 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. |