so clearly distinguish the works of Michel Angelo from much of Greek sculpture.
We have seen that the human race arrives at higher stages of development by undergoing trials and hardships. It is clear, therefore, that the theory which traces the genesis of the moral instincts to civil or religious commands and punishments must be regarded as one-sided. Although the theory contains some truth, yet the roots of morality lie deeper. Not any consideration over what is good and useful, bad and hurtful, is the source of the moral feelings, but they spring from a deeper natural source. We here meet an inexhaustible and independent store of forces which manifest themselves as the reaction of living beings against disturbing external agencies. The narrow bounds of individual life place a limit to the use of these natural forces, but the race knows no such bounds, and its gradual increase in intellectual and moral power no cessation. Although human life seems scarcely conceivable without evil, yet we may conclude that it will more and more escape from trouble and reach a stage where only labor and the death of the individual will continue to harass it. The explanation usually given of the fact that a muscle grows stronger by exercise is that a great chemical change takes place and the organ in motion receives a greater supply of blood, and thus its supply of nourishment is increased. This explanation is insufficient, for it overlooks the fact that not only does the mass of the muscle increase, but that its composition changes and becomes more purposive. There would be nothing mysterious if the process only supplied the waste, but there is here a new effort to appropriate an increased amount of force. Von S. claims also to have established by experiments that animals which are made to undergo a fasting period become afterwards stronger than those which are fed regularly. This was true, although the total amount of food consumed during the whole time of the experiment was less than that consumed by the others. The hunger, he concludes, must have called out a force sui generis which rendered the smaller amount of food more effective. He refers to the beneficial effects upon the system of certain sicknesses, to the effect of cold — itself a negative and destructive agent — in increasing the vigor of the organism, and to the immunity from certain diseases which result from inoculation. All these facts seem to the author to point to a basal force (Kraftanlage) the steady increase of which cannot be explained on physical or chemical principles. True, the increase of energy in any individual is limited by the span of his years, yet we can never say, in
