of necessity for the mind to feign any resembling and contiguous objects; and if it feigns such, there is as little necessity for it always to confine itself to the same, without any difference or variation. And indeed such a fiction is founded on so little reason, that nothing but pure caprice can determine the mind to form it; and that principle being fluctuating and uncertain, it is impossible it can ever operate with any considerable degree of force and constancy. The mind forsees and anticipates the change; and even from the very first instant feels the looseness of its actions, and the weak hold it has of its objects. And as this imperfection is very sensible in every single instance, it still encreases by experience and observation, when we compare the several instances we may remember, and form a general rule against the reposing any assurance in those momentary glimpses of light, which arise in the imagination from a feigned resemblance and contiguity.
The relation of cause and effect has all the opposite advantages. The objects it presents are fixt and unalterable. The impressions of the memory never change in any considerable degree; and each impression draws along with it a precise idea, which takes its place in the imagination as something solid and real, certain and invariable. The thought is always determined to pass from the impression to the idea, and from that particular impression to that particular idea, without any choice or hesitation.
But not content with removing this objection, I shall endeavour to extract from it a proof of the present doctrine. Contiguity and resemblance have an effect much inferior to causation; but still have some effect, and augment the conviction of any opinion, and the vivacity of any conception. If this can be proved in several new instances, beside what we have already observed, it will be allowed no inconsiderable argument, that belief is nothing but a lively idea related to a present impression.
To begin with contiguity; it has been remarked among the Mahometans as well as Christians, that those pilgrims, who have seen MECCA or the HOLY LAND, are ever after more faithful and zealous believers, than those who have not had that advantage. A man, whose memory presents him with a lively image of the Red-Sea, and the Desert, and Jerusalem, and Galilee, can never doubt of any miraculous events, which are related either by Moses or the Evangelists. The lively idea of the places passes by an easy transition to the facts, which are supposed to have been related to them by contiguity, and encreases the belief by encreasing the vivacity of the conception. The remembrance of these fields and rivers has the same influence on the vulgar as a new argument; and from the same causes.
We may form a like observation concerning resemblance. We have remarked, that the conclusion, which we draw from a present object to its absent cause or effect, is never founded on any qualities, which we observe in that object, considered in itself, or, in other words, that it is impossible to determine, otherwise than by experience, what will result from any phenomenon, or what has preceded it. But though this be so evident in itself, that it seemed not to require any, proof; yet some philosophers have imagined that there is an apparent cause for the communication of motion, and that a reasonable man might immediately infer the motion of one body from the impulse of another, without having recourse to any past observation. That this opinion is false will admit of an easy proof. For if such an inference may be drawn merely from the ideas of body, of motion, and of impulse, it must amount to a demonstration, and must imply the absolute impossibility of any contrary supposition. Every effect, then, beside the communication of motion, implies a formal contradiction; and it is impossible not only that it can exist, but also that it can be conceived. But we may soon satisfy ourselves of the contrary, by forming a clear and consistent idea of one body's moving upon another, and of its rest immediately upon the contact, or of its returning back in the same line in which it came; or of its annihilation; or circular or elliptical motion: and in short, of an infinite number of other changes, which we may suppose it to undergo. These suppositions are all consistent and natural; and the reason, Why we imagine the communication of motion to be more consistent and natural not only than those suppositions, but also than any other natural effect, is founded on the relation of resemblance betwixt the cause and effect, which is here united to experience, and binds the objects in the closest and most intimate manner to each other, so as to make us imagine them to be absolutely inseparable. Resemblance, then, has the same or a parallel influence with experience; and as the only immediate effect of experience is to associate our ideas together, it follows, that all belief arises from the association of ideas, according to my hypothesis.
It is universally allowed by the writers on optics, that the eye at all times sees an equal number of physical points, and that a man on the top of a mountain has no larger an image presented to his senses, than when he is cooped up in the narrowest court or chamber. It is only by experience that he infers the greatness of the object from some peculiar qualities of the image; and this inference of the judgment he confounds with sensation, as is common on other occasions. Now it is evident, that the inference of the judgment is here much more lively than what is usual in our common reasonings, and that a man has a more vivid conception of the vast extent of the ocean from the image he receives by the eye, when he stands on the top of the high promontory, than merely from hearing the roaring of the waters. He feels a more sensible pleasure from its magnificence; which is a proof of a more lively idea: And he confounds his judgment with sensation, which is another proof of it. But as the inference is equally certain and immediate in both cases, this superior vivacity of our conception in one case can proceed from nothing but this, that in drawing an inference from the sight, beside the customary conjunction, there is also a resemblance betwixt the image and the object we infer; which strengthens the relation, and conveys the vivacity of the impression to the related idea with an easier and more natural movement.
No weakness of human nature is more universal and conspicuous than what we commonly call CREDULITY, or a too easy faith in the testimony of others; and this weakness is also very naturally accounted for from the influence of resemblance. When we receive any matter of fact upon human testimony, our faith arises from the very same origin as our inferences from causes to effects, and from effects to causes; nor is there anything but our experience of the governing principles of human nature, which can give us any assurance of the veracity of men. But though experience be the true standard of this, as well as of all other judgments, we seldom regulate ourselves entirely by it; but have a remarkable propensity to believe whatever is reported, even concerning apparitions, enchantments, and prodigies, however contrary to daily experience and observation. The words or discourses of others have an intimate connexion with certain ideas in their mind; and these ideas have also a connexion with the facts or objects, which they represent. This latter connexion is generally much over-rated, and commands our assent beyond what experience will justify; which can proceed from nothing beside the resemblance betwixt the ideas and the facts. Other effects only point out their causes in an oblique manner; but the testimony of men does it directly, and is to be considered as an image as well as an effect. No wonder, therefore, we are so rash in drawing our inferences from it, and are less guided by experience in our judgments concerning it, than in those upon any other subject.
As resemblance, when conjoined with causation, fortifies our reasonings; so the want of it in any very great degree is able almost entirely to destroy them. Of this there is a remarkable instance in the universal carelessness and stupidity of men with regard to a future state, where they show as obstinate an incredulity, as they do a blind credulity on other occasions. There is not indeed a more ample matter of wonder to the studious, and of regret to the pious man, than to observe the negligence of the bulk of mankind concerning their approaching condition; and it is with reason, that many eminent theologians have not scrupled to affirm, that though the vulgar have no formal principles of infidelity, yet they are really infidels in their hearts, and have nothing like what we can call a belief of the eternal duration of their souls. For let us consider on the one hand what divines have displayed with such eloquence concerning the importance of eternity; and at the same time reflect, that though in matters of rhetoric we ought to lay our account with some exaggeration, we must in this case allow, that the strongest figures are infinitely inferior to the subject: And after this let us view on the other hand, the prodigious security of men in this particular: I ask, if these people really believe what is inculcated on them, and what they pretend to affirm; and the answer is obviously in the negative. As belief is an act of the mind arising from custom, it is not strange the want of resemblance should overthrow what custom has established, and diminish the force of the idea, as much as that