In the first place, we find the great kinds of literature, if not finally and exhaustively, yet in nearly all their most important points, discerned, marked off, and as far as possible furnished with definitions. The most important of all demarcations, that between poetry and prose, is rather taken for granted than definitely argued out; but we see that, with whatever hesitations and reservations, it _is_ taken for granted. So, too, with the kinds of poetry itself. If prose is inadequately treated, both in general and in its departments, we have been able to assign something like a reason for that; and a good deal is actually done in this direction. In other words, the field, the “claim,” of literary criticism is pretty fairly pegged out. In the second place, the only sound plan—that of taking actually accomplished works of art and endeavouring to ascertain how it is that they give the artistic pleasure—is, with whatever falterings, pretty steadily pursued. The critic, as Simylus, Aristotle’s own contemporary, has it, consistently endeavours to “grasp” his subject; and he does grasp it over and over again. Let us review our positive gains from this grasp. That the “Imitation” doctrine of the _Poetics_ is in some respects disputable need not be denied; and that it lends itself rather easily to serious misconstruction is certain. [Sidenote: “_Imitation._”] But let us remember also that it is an attempt—probably the first attempt, and one which has not been much bettered in all the improvements upon it—to adjust those proportions of nature and art which actually do exist in poetry. For by Imitation, whatever Aristotle did mean exactly, he most certainly did _not_ mean mere copying, mere tracing or plaster-of-Paris moulding from nature. It is not quite impossible that his at first sight puzzling objection to Alcidamas' use of the “mirror” as a description of the _Odyssey_ had something to do with this.[54] A mirror, he would or might have said, reproduces passively, slavishly, and without selection or alteration: the artist selects, adapts, adjusts, and if necessary alters. Now this is the true doctrine, and all deviations from, it, whether in the shape of realism, impressionism,[55] and the like, in the one direction, or of adherence to generalised convention on the other, have always led to mischief soon or late. The artist must be the mime, not the mirror: the reasonable, discreet, free-willed agent, not the passive medium. The single dictum that poetry does not necessarily deal with the actual but with the possible—that it is therefore “more philosophic,” higher, more universal, than history, though it requires both extension and limitation, will put us more in the true critical position than any dictum that we find earlier, or (it may be very frankly added) than most that we shall find later.[56] Footnote 54: