Section X. Of the influence of belief. (cont.)
Nor will it be amiss to remark, that as a lively imagination very often degenerates into madness or folly, and bears it a great resemblance in its operations; so they influence the judgment after the same manner, and produce belief from the very same principles. When the imagination, from any extraordinary ferment of the blood and spirits, acquires such a vivacity as disorders all its powers and faculties, there is no means of distinguishing betwixt truth and falsehood; but every loose fiction or idea, having the same influence as the impressions of the memory, or the conclusions of the judgment, is received on the same footing, and operates with equal force on the passions. A present impression and a customary transition are now no longer necessary to enliven our ideas. Every chimera of the brain is as vivid and intense as any of those inferences, which we formerly dignified with the name of conclusions concerning matters of fact, and sometimes as the present impressions of the senses.
We may observe the same effect of poetry in a lesser degree; and this is common both to poetry and madness, that the vivacity they bestow on the ideas is not derived from the particular situations or connections of the objects of these ideas, but from the present temper and disposition of the person. But how great soever the pitch may be, to which this vivacity rises, 'tis evident, that in poetry it never has the same feeling with that which arises in the mind, when we reason, tho' even upon the lowest species of probability. The mind can easily distinguish betwixt the one and the other; and whatever emotion the poetical enthusiasm may give to the spirits, 'tis still the mere phantom of belief or persuasion. The case is the same with the idea, as with the passion it occasions. There is no passion of the human mind but what may arise from poetry; tho' at the same time the feelings of the passions are very different when excited by poetical fictions, from what they are when they are from belief and reality. A passion, which is disagreeable in real life, may afford the highest entertainment in a tragedy, or epic poem. In the latter case, it lies not with that weight upon us: It feels less firm and solid: And has no other than the agreeable effect of exciting the spirits, and rousing the attention. The difference in the passions is a clear proof of a like difference in those ideas, from which the passions are derived. Where the vivacity arises from a customary conjunction with a present impression; tho' the imagination may not, in appearance, be so much moved; yet there is always something more forcible and real in its actions, than in the fervors of poetry and eloquence. The force of our mental actions in this case, no more than in any other, is not to be measured by the apparent agitation of the mind. A poetical description may have a more sensible effect on the fancy, than an historical narration. It may collect more of those circumstances, that form a complete image or picture. It may seem to set the object before us in more lively colours. But still the ideas it presents are different to the feeling from those, which arise from the memory and the judgment. There is something weak and imperfect amidst all that seeming vehemence of thought and sentiment, which attends the fictions of poetry.
We shall afterwards have occasion to remark both the resemblance and differences betwixt a poetical enthusiasm, and a serious conviction. In the meantime I cannot forebear observing, that the great difference in their feeling proceeds in some measure from reflection and general rules. We observe, that the vigour of conception, which fictions receive from poetry and eloquence, is a circumstance merely accidental, of which every idea is equally susceptible; and that such fictions are connected with nothing that is real. This observation makes us only lend ourselves, so to speak, to the fiction: But causes the idea to feel very different from the eternal established persuasions founded on memory and custom. They are somewhat of the same kind: But the one is much inferior to the other, both in its causes and effects.
A like reflection on general rules keeps us from augmenting our belief upon every increase of the force and vivacity of our ideas. Where an opinion admits of no doubt, or opposite probability, we attribute to it a full conviction: tho' the want of resemblance, or contiguity, may render its force inferior to that of other opinions. 'Tis thus the understanding corrects the appearances of the senses, and makes us imagine, that an object at twenty foot distance seems even to the eye as large as one of the same dimensions at ten.
We may observe the same effect of poetry in a lesser degree; only with this difference, that the least reflection dissipates the illusions of poetry, and places the objects in their proper light. 'Tis however certain, that in the warmth of a poetical enthusiasm, a poet has a counterfeit belief, and even a kind of vision of his objects: And if there be any shadow of argument to support this belief, nothing contributes more to his full conviction than a blaze of poetical figures and images, which have their effect upon the poet himself, as well as upon his readers.