It is not surprising that there should be an internal sensation which warns us of perils, and causes us to recognize the circumstances favorable to life. If science in these days demonstrates that the means for preserving even material life correspond to the moral "virtues," we may conclude that we shall be able to divine what is necessary to life by means of the internal sensibility. Have not the biological sciences demonstrated an analogous fact? The biometer applied to man has made it possible to reconstruct the absolutely average man, that is to say, the man whose body gives average measurements in every part; and these average measurements have been found, by means of the statistical and morphological studies of medicine, to correspond to "normality." Thus the average man would be a man so perfectly constructed that he has no morphological predisposition to disease of the organs. When the figure of a man was reconstructed in accordance with average biometrical proportions, it was found to correspond in a remarkable manner to the proportions of Greek statues. This fact helped to give a new interpretation to "aesthetic sentiment." It was evidently by means of aesthetic feeling that the eye of the Greek artist was able to extract the average measurement of every organ, and to construct a marvelous and exact whole therewith. The "enjoyment" of the artist was his enjoyment of the "beautiful"; but he felt even more profoundly that which contained the triumph of life, and distinguished it from the errors of nature, which predispose to illness. The triumph of creation can give an intimate pleasure to him who can "feel it"; errors, even slight, will then be perceived as discords. Aesthetic education is, in short, akin to the mathematical approximation towards the absolute average; the more it is possible to approach to the true measure in its extreme limits, and the closer we can get to this, the more possible does it become to have an absolute means of comparison for the consideration of deviations. The great artist is thus able to recognize the beautiful in a detail even in the midst of other discordant details; and the more capable he is of possessing an absolute sense of the beautiful, the more readily will he perceive any disproportion of form.