From “Discourses on Art.”

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 a 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 further; 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 at 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, like every other effect, as they must have their cause, must likewise have their 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 observations, or of such a nice texture as not easily to admit being expressed in words; especially as artists are not very frequently skillful in that mode of communicating ideas. Unsubstantial, however, as these rules may seem, and difficult as it may be to convey them in writing, they are still seen and felt in the mind of the artist; and he works from them with as much certainty as if they were embodied, as I may say, upon paper. It is true these refined principles cannot be always made palpable, like the more gross rules of art, yet it does not follow, but that the mind may be put in such a train, that it shall perceive, by a kind of scientific sense, that propriety, which words, particularly words of unpracticed writers, such as we are, can but very feebly suggest.

  Invention is one of the great marks of Genius; but if we consult experience we shall find that it is by being conversant with the inventions of others that we learned to invent, as by reading the thoughts of others we learn to think.