Evolution is not, as the name suggests, a process of unfolding; evolution is, as Christian Friedrich Wolff calls it, an “epigenesis,” i. e. the process of the additional growth of new formations. The chick is something different in kind from the egg. The unity of the egg-cell organism in the yolk is radically different from the unity of the full-fledged chick. The former shows traces of irritability but not of consciousness, while the latter exhibits unmistakable symptoms of psychical activity. The formation of the chicken-soul is a new formation as much as the growth of feathers. The feathers of the chick are an additional growth; there are no latent feathers in the egg. We might express ourselves to the effect that the egg contains the potential existence of feathers, but with the same logic we might say the egg contains a potential chicken broth. It is however true that something remains constant in the process of growth. There is a preservation of form in the constant change of material particles and this is the physiological basis of memory, so that a man of eighty may say “I remember when I was a child,” although not one particle of the substance of which the child consisted is left in him. The continuity produced through this preservation of form makes growth and evolution possible. The preservation of memory-structures constitutes the possibility of reviving the feelings of the past, it constitutes a preservation of soul. The material parts of the body are thrown out but the form being preserved, the soul remains. And this preservation of the soul is the basis of its additional growth through new and enlarged experience. The soul of the child is not lost in the man, it is preserved. It has lost certain features and at the same time it has gained new features, it has developed, and the unity of the soul has more or less changed with the development. What is true of the individual is also true of mankind. Mankind as a whole is different in the savage and in civilised society. Nevertheless the latter has developed from the former. Certain traits have been dropped, other radically new features have appeared. That which was valuable in the soul of primitive man is not lost. The better part of his soul still lives in the highest developed man of to-day; the continuity is preserved. And to-day all our moral instruction aims at this, so to live that our souls also will be preserved in the future evolution of humanity. The gist of ethics is to make the soul immortal.[49] X. PROFESSOR MACH’S POSITION.