On the Sublime and Beautiful/Part II/Chapter 11
TO the sublime in building, greatness of dimension seems requisite; for on a few parts, and those small, the imagination cannot rise to any idea of infinity. No greatness in the manner can effectually compensate for the want of proper dimensions. There is no danger of drawing men into extravagant designs by this rule; it carries its own caution along with it. Because too great a length in buildings destroys the purpose of greatness, which it was intended to promote; the perspective will lessen it in height as it gains in length; and will bring it at last to a point; turning the whole figure into a sort of triangle, the poorest in its effect of almost any figure that can be presented to the eye. I have ever observed, that colonnades and avenues of trees of a moderate length, were, without comparison, far grander, than when they were suffered to run to immense distances. A true artist should put a generous deceit on the spectators, and effect the noblest designs by easy methods. Designs that are vast only by their dimensions, are always the sign of a common and low imagination. No work of art can be great, but as it deceives; to be otherwise is the prerogative of nature only. A good eye will fix the medium betwixt an excessive length or height, (for the same objection lies against both,) and a short or broken quantity; and perhaps it might be ascertained to a tolerable degree of exactness, if it was my purpose to descend far into the particulars of any art.