We have already examined at length what the general principle of the classical ideal is. Our present inquiry is therefore limited to the particular mode under which this principle is realized through the medium of sculpture in the human form. In this connection the lines of difference between the human physiognomy, expressive as it is of spiritual life and the general build of the animal organism, which is unable to pass beyond the mere expression of natural life in its unbroken association with natural wants and an organism that is exclusively adapted to their satisfaction, will supply us with a standard of comparison which carries us considerably further. Yet even such a standard is still somewhat indefinite for the reason that the human form alone neither is as bodily form, or as an expression of Spirit, wholly and as we find it first of ideal type. On the contrary we may observe with more closeness from the fine masterpieces of Greek sculpture what the ideal of sculpture in the spiritually fine expression of its creations has to bring before us. It was pre-eminently Winckelmann who, with this intimate knowledge of and devotion for art of this kind, and by means of his receptive enthusiasm, no less than his intelligence and critical faculty, made an end of indefinite statements over the Ideal of Greek beauty by leaving the characterization of detail in the form at once distinct and precise, an endeavour which by itself is full of instruction. No doubt the results he obtained supply abundant opportunity for further criticism, exceptions, and the like; but we should be careful, before attempting to criticize details and errors in his work, not to obscure the main result which he established. However far aesthetic science may extend its borders that at least must be presupposed as essential. Assuming this, it cannot, however, be denied that since Winckelmann's death our knowledge of the antique has not only been essentially enlarged in the number of examples submitted to criticism, but also has been placed on a securer basis in its relation to the style of these works and the true appreciation of their beauty.