| But it is certainly true, that any reasoning is always the more convincing, the more single and united it is to the eye, and the less exercise it gives to the imagination to collect all its parts, and run from them to the correlative idea, which forms the conclusion. |
| The labour of the thought disturbs the regular progress of the sentiments, as we shall observe presently.[Part IV. SECT. 1.] The idea strikes not on us with ouch vivacity; and consequently has no such influence on the passion and imagination. |
| From the same principles we may account for those observations of the CARDINAL DE RETZ, that there are many things, in which the world wishes to be deceived; and that it more easily excuses a person in acting than in talking contrary to the decorum of his profession and character. |
| A fault in words is commonly more open and distinct than one in actions, which admit of many palliating excuses, and decide not so clearly concerning the intention and views of the actor. |
| Thus it appears upon the whole, that every kind of opinion or judgment, which amounts not to knowledge, is derived entirely from the force and vivacity of the perception, and that these qualities constitute in the mind, what we call the BELIEF Of the existence of any object. |
| This force and this vivacity are most conspicuous in the memory; and therefore our confidence in the veracity of that faculty is the greatest imaginable, and equals in many respects the assurance of a demonstration. |
| The next degree of these qualities is that derived from the relation of cause and effect; and this too is very great, especially when the conjunction is found by experience to be perfectly constant, and when the object, which is present to us, exactly resembles those, of which we have had experience. |
| But below this degree of evidence there are many others, which have an influence on the passions and imagination, proportioned to that degree of force and vivacity, which they communicate to the ideas. |
| It is by habit we make the transition from cause to effect; and it is from some present impression we borrow that vivacity, which we diffuse over the correlative idea. |
| But when we have not observed a sufficient number of instances, to produce a strong habit; or when these instances are contrary to each other; or when the resemblance is not exact; or the present impression is faint and obscure; or the experience in some measure obliterated from the memory; or the connexion dependent on a long chain of objects; or the inference derived from general rules, and yet not conformable to them: In all these cases the evidence diminishes by the diminution of the force and intenseness of the idea. |
| This therefore is the nature of the judgment and probability. |
| What principally gives authority to this system is, beside the undoubted arguments, upon which each part is founded, the agreement of these parts, and the necessity of one to explain another. |
| The belief, which attends our memory, is of the same nature with that, which is derived from our judgments: Nor is there any difference betwixt that judgment, which is derived from a constant and uniform connexion of causes and effects, and that which depends upon an interrupted and uncertain. |
| It is indeed evident, that in all determinations, where the mind decides from contrary experiments, it is first divided within itself, and has an inclination to either side in proportion to the number of experiments we have seen and remember. |
| This contest is at last determined to the advantage of that side, where we observe a superior number of these experiments; but still with a diminution of force in the evidence correspondent to the number of the opposite experiments. |
| Each possibility, of which the probability is composed, operates separately upon the imagination; and it is the larger collection of possibilities, which at last prevails, and that with a force proportionable to its superiority. |
| All these phenomena lead directly to the precedent system; nor will it ever be possible upon any other principles to give a satisfactory and consistent explication of them. |
| Without considering these judgments as the effects of custom on the imagination, we shall lose ourselves in perpetual contradiction and absurdity. |
| SECT. XIV. OF THE IDEA OF NECESSARY CONNEXION. |
| Having thus explained the manner, in which we reason beyond our immediate impressions, and conclude that such particular causes must have such particular effects; we must now return upon our footsteps to examine that question, which [SECT. 2.] first occured to us, and which we dropt in our way, viz. |
| What is our idea of necessity, when we say that two objects are necessarily connected together. |