The common people, ignorant of the principles of art, talk the same language even to this day.  But when it was found that every man could be taught to do this, and a great deal more, merely by the observance of certain precepts, the name of genius then shifted its application, and was given only to those who added the peculiar character of the object they represented; to those who had invention, expression, grace, or dignity; or, in short, such qualities or excellences the producing of which could not then be taught by any known and promulgated rules.

We are very sure that the beauty of form, the expression of the passions, the art of composition, even the power of giving a general air of grandeur to your work, is at present very much under the dominion of rules.  These excellences were, heretofore, considered merely as the effects of genius; and justly, if genius is not taken for inspiration, but as the effect of close observation and experience.

He who first made any of these observations and digested them, so as to form an invariable principle for himself to work by, had that merit; but probably no one went very far at once; and generally the first who gave the hint did not know how to pursue it steadily and methodically, at least not in the beginning.  He himself worked on it, and improved it; others worked more, and improved farther, until the secret was discovered, and the practice made as general as refined practice can be made.  How many more principles may be fixed and ascertained we cannot tell; but as criticism is likely to go hand in hand with the art which is its subject, we may venture to say that as that art shall advance, its powers will be still more and more fixed by rules.

But by whatever strides criticism may gain ground, we need be under no apprehension that invention will ever be annihilated or subdued, or intellectual energy be brought entirely within the restraint of written law.  Genius will still have room enough to expatiate, and keep always the same distance from narrow comprehension and mechanical performance.

What we now call genius begins, not where rules, abstractedly taken, end, but where known vulgar and trite rules have no longer any place.  It must of necessity be that even works of genius, as well as every other effect, as it must have its cause, must likewise have its rules; it cannot be by chance that excellences are produced with any constancy, or any certainty, for this is not the nature of chance, but the rules by which men of extraordinary parts, and such as are called men of genius work, are either such as they discover by their own peculiar observation, or of such a nice texture as not easily to admit handling or expressing in words, especially as artists are not very frequently skilful in that mode of communicating ideas.