Another root of the romantic spirit was the sense of, and naturally the belief in, a world not to be felt of the senses or analysed by the understanding; which was within the apparent world as its substance or soul, or beyond it as the power by which it existed; and this mystic belief took, among poets, philosophers, theologians, warriors and the common people, a thousand forms, ranging from full-schemed philosophies to the wildest superstitions. It tended, in its extremes, to make this world a shadow, a dream; and our life only a real life when it habitually dwelt in the mystic region mortal eye could not see, whose voices mortal ear could not receive. Out of this root, which shot its first fibres into the soul of humanity in the days of the earliest savage and separated him by an unfathomable gulf from the brute, arose all the myths and legends and mystic stories which fill romance. Out of it developed the unquenchable thirst of those of the romantic temper for communion with the spiritual beings of this mystic world; a thirst which, however repressed for a time, always arises again; and is even now arising among the poets of to-day. In Browning's view of the natural world some traces of this element of the romantic spirit may be distinguished, but in his poetry of Man it scarcely appears. Nor, indeed, is he ever the true mystic. He had too much of the sense which handles daily life; he saw the facts of life too clearly, to fall into the vaguer regions of mysticism. But one part of its region, and of the romantic spirit, so incessantly recurs in Browning that it may be said to underlie the whole of his work. It is that into which the thoughts and passions of the romantic poets in all ages ran up, as into a goal--the conception of a perfect world, beyond this visible, in which the noble hopes, loves and work of humanity--baffled, limited, and ruined here--should be fulfilled and satisfied. The Greeks did not frame this conception as a people, though Plato outreached towards it; the Romans had it not, though Vergil seems to have touched it in hours of inspiration. The Teutonic folk did not possess it till Christianity invaded them. Of course, it was alive like a beating heart in Christianity, that most romantic of all religions. But the Celtic peoples did conceive it before Christianity and with a surprising fulness, and wherever they went through Europe they pushed it into the thought, passions and action of human life. And out of this conception, which among the Irish took form as the Land of Eternal Youth, love and joy, where human trouble ceased, grew that element in romance which is perhaps the strongest in it--the hunger for eternity, for infinite perfection of being, and, naturally, for unremitting pursuit of it; and among Christian folk for a life here which should fit them for perfect life to come. Christian romance threw itself with fervour into that ideal, and the pursuit, for example, of the Holy Grail