Indeed the works of art have need of the whole advantage of this line to make up for its other deficiencies: for tho' in nature's works the line of beauty is often neglected, or mixt with plain lines, yet so far are they from being defective on this account, that by this means there is exhibited that infinite variety of human forms which always distinguishes the hand of nature from the limited and insufficient one of art; and as thus she for the sake of variety upon the whole, deviates sometimes into plain and inelegant lines, if the poor artist is but able now and then to correct and give a better taste to some particular part of what he imitates, by having learnt so to do from her more perfect works, or copying from those that have, ten to one he grows vain upon it, and fancies himself a nature-mender; not considering, that even in these, the meanest of her works, she is never wholly destitute of such lines of beauty and other delicacies, as are not only beyond his narrow reach, but are seen wanting even in the most celebrated attempts to rival her. But to return, As to what we call plain lines, there is this remarkable effect constantly produced by them, that being more or less conspicuous in any kind of character or expression of the face, they bring along with them certain degrees of a foolish or ridiculous aspect. It is the inelegance of these lines which more properly belonging to inanimate bodies, and being seen where lines of more beauty and taste are expected, that renders the face silly and ridiculous. See Chapter VI, p. 31. Children in infancy have movements in the muscles of their faces peculiar to their age, as an uninformed and unmeaning stare, an open mouth, and simple grin: all which expressions are chiefly formed of plain curves, and these movements and expressions ideots are apt to retain; so that in time they mark their faces with these uncouth lines; and when the lines coincide and agree with the natural forms of the features, it becomes a more apparent and confirmed character of an ideot. These plain shapes last mentioned, sometimes happen to people of the best sense, to some when the features are at rest, to others when they are put into motion; which a variety of constant regular movements proceeding from a good understanding, and fashioned by a genteel education, will often by degrees correct into lines of more elegance.