| The FIRST may be explained after this manner. |
| When the mind forms a reasoning concerning any matter of fact, which is only probable, it casts its eye backward upon past experience, and transferring it to the future, is presented with so many contrary views of its object, of which those that are of the same kind uniting together, and running into one act of the mind, serve to fortify and inliven it. |
| But suppose that this multitude of views or glimpses of an object proceeds not from experience, but from. |
| a voluntary act of the imagination; this effect does not follow, or at least, follows not in the same degree. |
| For though custom and education produce belief by such a repetition, as is not derived from experience, yet this requires a long tract of time, along with a very frequent and undesigned repetition. |
| In general we may pronounce, that a person who would voluntarily repeat any idea in his mind, though supported by one past experience, would be no more inclined to believe the existence of its object, than if he had contented himself with one survey of it. |
| Beside the effect of design; each act of the mind, being separate and independent, has a separate influence, and joins not its force with that of its fellows. |
| Not being united by any common object, producing them, they have no relation to each other; and consequently make no transition or union of forces. |
| This phaenomenon we shall understand better afterwards. |
| My second reflection is founded on those large probabilities, which the mind can judge of, and the minute differences it can observe betwixt them. |
| When the chances or experiments on one side amount to ten thousand, and on the other to ten thousand and one, the judgment gives the preference to the latter, upon account of that superiority; though it is plainly impossible for the mind to run over every particular view, and distinguish the superior vivacity of the image arising from the superior number, where the difference is so inconsiderable. |
| We have a parallel instance in the affections. |
| It is evident, according to the principles above-mentioned, that when an object produces any passion in us, which varies according to the different quantity of the object; I say, it is evident, that the passion, properly speaking, is not a simple emotion, but a compounded one, of a great number of weaker passions, derived from a view of each part of the object. |
| For otherwise it were impossible the passion should encrease by the encrease of these parts. |
| Thus a man, who desires a thousand pound, has in reality a thousand or more desires which uniting together, seem to make only one passion; though the composition evidently betrays itself upon every alteration of the object, by the preference he gives to the larger number, if superior only by an unite. |
| Yet nothing can be more certain, than that so small a difference would not be discernible in the passions, nor coued render them distinguishable from each other. |
| The difference, therefore, of our conduct in preferring the greater number depends not upon our passions, but upon custom, and general rules. |
| We have found in a multitude of instances, that the augmenting the numbers of any sum augments the passion, where the numbers are precise and the difference sensible. |
| The mind can perceive from its immediate feeling, that three guineas produce a greater passion than two; and this it transfers to larger numbers, because of the resemblance; and by a general rule assigns to a thousand guineas, a stronger passion than to nine hundred and ninety nine. |
| These general rules we shall explain presently. |
| But beside these two species of probability, which a-re derived from an imperfect experience and from contrary causes, there is a third arising from ANALOGY, which differs from them in some material circumstances. |