All sound study is comparative. We must place other literatures beside our own, if we desire to appraise rightly our national genius, its capacities, and its creations. We find our English writers composing their works in certain forms, and giving expression to a certain range of ideas. How came they to employ these particular forms of creation? How did they arrive at these particular ideas? How is it with other nations? Have they built upon the same lines and with the same materials, or how is it with them? Have we borrowed from them, or they from us? If there have been borrowings, when and in what measure did they occur? Looking back over the changes of spirit and form which our poetry, for example, has undergone, we shall encourage altogether false notions of the causes of such changes, unless we see how, every now and then, a shower of new ideas, a stream of new light, has come in from abroad. Most readers know in some vague way that Chaucer avows or betrays his debts to France and Italy; that Shakespeare did not invent his own plots, but borrowed from Italians, from Plautus, from Plutarch, and others; that Milton was steeped in the Greek, Latin, and Italian classics. But we want to know more than this. We want to perceive with some definiteness how far the whole course of English literature has been enriched by tributary streams, and what sort of waters they brought. It would be instructive to draw a diagram of our literary history; to liken it to the course of a river, and to picture its various fountain-heads and tributaries pouring in their several quotas at their several times. In all modern literatures there is a large proportion which is unoriginal to them. Milton has been mentioned already. Those who read only English works find Milton full of nobility of thought and imagery. Yet, before Milton produced his greater poems, he had read, re-read, and deliberately steeped himself in, the literature of Greece, Rome, modern Italy, and France. Precisely how much of Milton is made up of Homer, Euripides, Virgil, Dante, Ariosto, and other predecessors, can only be known to such as have those authors at their finger-ends. Shelley, again, is commonly regarded as one of the most daringly original of English writers. Yet Shelley’s mind was an amalgam of himself, Homer, Euripides, Plato, Virgil, Dante, Calderon, Goethe; and this, once more, is but another way of saying that it had incorporated the genius of generations of Greeks, Romans, Spaniards, Italians, and Germans. We cannot therefore arrive at the true genius of Milton or of Shelley, or speak understandingly of their originality, until we have surveyed those other literatures and their relations with our own.