[79] Coke upon Littleton, p. 71. [80] Practical writers upon the fine arts will attempt any thing, being blind both to the difficulty and danger. De Piles, accounting why contrast is agreeable, says, “That it is a sort of war which puts the opposite parties in motion.” Thus, to account for an effect of which there is no doubt, any cause, however foolish, is made welcome. [81] Chap. 2. part 5. [82] The examples above given are of subjects that can be brought to an end or conclusion. But the same uneasiness is perceptible with respect to subjects that admit not any conclusion; witness a series that has no end, commonly called _an infinite series_. The mind running along such a series, begins soon to feel an uneasiness, which becomes more and more sensible in continuing its progress. An unbounded prospect doth not long continue agreeable. We soon feel a slight uneasiness, which increases with the time we bestow upon the object. In order to find the cause of this uneasiness, we first take under consideration an avenue without a terminating object. Can a prospect without any termination be compared to an infinite series? There is one striking difference, that with respect to the eye no prospect can be unbounded. The quickest eye commands but a certain length of space; and there it is bounded, however obscurely. But the mind perceives things as they exist; and the line is carried on in idea without end. In that respect an unbounded prospect is similar to an infinite series. In fact, the uneasiness of an unbounded prospect differs very little in its feeling from that of an infinite series; and therefore we may reasonably conclude that both proceed from the same cause. We next consider a prospect unbounded every way, as for example, a great plain, or the ocean, viewed from an eminence. We feel here an uneasiness occasioned by the want of an end or termination, precisely as in the other cases. A prospect unbounded every way is indeed so far singular, as at first to be more pleasant than a prospect that is unbounded in one direction only, and afterward to be more painful. But these circumstances are easily explained without breaking in upon the general theory. The pleasure we feel at first is a strong emotion of grandeur, arising from the immense extension of the object. And to increase the pain we feel afterward for the want of a termination, there concurs a pain of a different kind, occasioned by stretching the eye to comprehend so great a prospect; a pain that gradually increases with the repeated efforts we make to grasp the whole.