In looking back to the great works of genius in former times, we are sometimes disposed to wonder at the little progress which has since been made in poetry, and in the arts of imitation in general.  But this is perhaps a foolish wonder.  Nothing can be more contrary to the fact, than the supposition that in what we understand by the fine arts, as painting, and poetry, relative perfection is only the result of repeated efforts in successive periods, and that what has been once well done, constantly leads to something better.  What is mechanical, reducible to rule, or capable of demonstration, is progressive, and admits of gradual improvement:  what is not mechanical, or definite, but depends on feeling, taste, and genius, very soon becomes stationary, or retrograde, and loses more than it gains by transfusion.  The contrary opinion is a vulgar error, which has grown up, like many others, from transferring an analogy of one kind to something quite distinct, without taking into the account the difference in the nature of the things, or attending to the difference of the results.  For most persons, finding what wonderful advances have been made in biblical criticism, in chemistry, in mechanics, in geometry, astronomy, &c. i.e. in things depending on mere inquiry and experiment, or on absolute demonstration, have been led hastily to conclude, that there was a general tendency in the efforts of the human intellect to improve by repetition, and, in all other arts and institutions, to grow perfect and mature by time.  We look back upon the theological creed of our ancestors, and their discoveries in natural philosophy, with a smile of pity:  science, and the arts connected with it, have all had their infancy, their youth, and manhood, and seem to contain in them no principle of limitation or decay:  and, inquiring no farther about the matter, we infer, in the intoxication of our pride, and the height of our self-congratulation, that the same progress has been made, and will continue to be made, in all other things which are the work of man.  The fact, however, stares us so plainly in the face, that one would think the smallest reflection must suggest the truth, and overturn our sanguine theories.  The greatest poets, the ablest orators, the best painters, and the finest sculptors that the world ever saw, appeared soon after the birth of these arts, and lived in a state of society which was, in other respects, comparatively barbarous.  Those arts, which depend on individual genius and incommunicable power, have always leaped at once from infancy to manhood, from the first rude dawn of invention to their meridian height and dazzling lustre, and have in general declined ever after.  This is the peculiar distinction and privilege of each, of science and of art:—­of the one, never to attain its utmost limit of perfection; and of the other, to arrive at it almost at once.  Homer, Chaucer, Spenser, Shakspeare, Dante, and Ariosto, (Milton alone