Hogarth, Beauty, and the Serpentine Line

...I shall proceed to consider the fundamental principles, which are generally allowed to give elegance and beauty, when duly blended together, to compositions of all kinds whatever; and point out to my readers, the particular force of each, in those compositions in nature and art, which seem most to please and entertain the eye, and give that grace and beauty, which is the subject of this enquiry. The principles I mean, are FITNESS, VARIETY, UNIFORMITY, SIMPLICITY, INTRICACY, and QUANTITY; .... all which co-operate in the production of beauty, mutually correcting and restraining each other occasionally.

Hogarth, Analysis of Beauty, 11-12.

And I beg the same things may be understood of these serpentine-lines, that I have said before of the waving-lines. For as among the vast variety of waving- lines that may be conceiv'd, there is but one that truly deserves the name of the line of beauty, so there is only one precise serpentine-line that I call the line of grace. Yet, even when they are made too bulging, or too tapering, though they certainly lose of their beauty and grace, they do not become so wholly void of it, as not to be of excellent service in compositions, where beauty and grace are not particularly design'd tobe express'd in their greatest perfection.

Hogarth, Analysis of Beauty, 52