46. In passing to the examination of our Author's theory as tested by the progress of Sculpture, we are still struck by his utter want of attention to physical advantages or difficulties. He seems to have forgotten from the first, that the mountains of Syene are not the rocks of Paros. Neither the social habits nor intellectual powers of the Greek had so much share in inducing his advance in Sculpture beyond the Egyptian, as the difference between marble and syenite, porphyry or alabaster. Marble not only gave the power, it actually introduced the _thought_ of representation or realization of form, as opposed to the mere suggestive abstraction: its translucency, tenderness of surface, and equality of tint tempting by utmost reward to the finish which of all substances it alone admits:--even ivory receiving not so delicately, as alabaster endures not so firmly, the lightest, latest touches of the completing chisel. The finer feeling of the hand cannot be put upon a hard rock like syenite--the blow must be firm and fearless--the traceless, tremulous difference between common and immortal sculpture cannot be set upon it--it cannot receive the enchanted strokes which, like Aaron's incense, separate the Living and the Dead. Were it otherwise, were finish possible, the variegated and lustrous surface would not exhibit it to the eye. The imagination itself is blunted by the resistance of the material, and by the necessity of absolute predetermination of all it would achieve. Retraction of all thought into determined and simple forms, such as might be fearlessly wrought, necessarily remained the characteristic of the school. The size of the edifice induced by other causes above stated, further limited the efforts of the sculptor. No colossal figure can be minutely finished; nor can it easily be conceived except under an imperfect form. It is a representation of Impossibility, and every effort at completion adds to the monstrous sense of Impossibility. Space would altogether fail us were we even to name one-half of the circumstances which influence the treatment of light and shade to be seen at vast distances upon surfaces of variegated or dusky color; or of the necessities by which, in masses of huge proportion, the mere laws of gravity, and the difficulty of clearing the substance out of vast hollows neither to be reached nor entered, bind the realization of absolute form. Yet all these Lord Lindsay ought rigidly to have examined, before venturing to determine anything respecting the mental relations of the Greek and Egyptian. But the fact of his overlooking these inevitablenesses of material is intimately connected with the worst flaw of his theory--his idea of a Perfection resultant from a balance of elements; a perfection which all experience has shown to be neither desirable nor possible. 47. His account of Niccola Pisano, the founder of the first great school of middle age sculpture, is thus introduced:-- * * *