[34] With such habitual impressions concerning the body, the physical nature of man, the Greek sculptor, in his later day, still free in imagination, through the lingering influence of those early dreams, may have more easily infused into human form the sense of sun, or lightning, or cloud, to which it was so closely akin, the spiritual flesh allying itself happily to mystical meanings, and readily expressing seemingly unspeakable qualities. But the human form is a limiting influence also; and in proportion as art impressed human form, in sculpture or in the drama, on the vaguer conceptions of the Greek mind, there was danger of an escape from them of the free spirit of air, and light, and sky. Hence, all through the history of Greek art, there is a struggle, a Streben, as the Germans say, between the palpable and limited human form, and the floating essence it is to contain. On the one hand, was the teeming, still fluid world, of old beliefs, as we see it reflected in the somewhat formless theogony of Hesiod; a world, the Titanic vastness of which is congruous with a certain sublimity of speech, when he has to speak, for instance, of motion or space; as the Greek language itself has a primitive copiousness and energy of words, for wind, fire, water, cold, sound--attesting a deep susceptibility to the impressions of those things--yet with edges, most often, melting into each other. On the other hand, there was that limiting, controlling tendency, [35] identified with the Dorian influence in the history of the Greek mind, the spirit of a severe and wholly self-conscious intelligence; bent on impressing everywhere, in the products of the imagination, the definite, perfectly conceivable human form, as the only worthy subject of art; less in sympathy with the mystical genealogies of Hesiod, than with the heroes of Homer, ending in the entirely humanised religion of Apollo, the clearly understood humanity of the old Greek warriors in the marbles of Aegina. The representation of man, as he is or might be, became the aim of sculpture, and the achievement of this the subject of its whole history; one early carver had opened the eyes, another the lips, a third had given motion to the feet; in various ways, in spite of the retention of archaic idols, the genuine human expression had come, with the truthfulness of life itself.