upon or are dependent upon some definite bodily state or condition. The moment that we recognize this we see that our sensations, ideas, and feelings are subject to control. It is only because our minds are in a world of causality, and subject to its laws, that education is possible. We can bring causes to bear upon a child and change the child. It is possible to build up ideas, ideals, and habits. And ideas, ideals, and habits constitute the man. Training is possible only because a child is a being that can be influenced. What any child will be when grown depends upon what kind of child it was at the beginning and upon the influences that affect it during its early life while it is growing into maturity. We need have no doubt about the outcome of any particular child if we know, with some degree of completeness, the two sets of factors that determine his life—his inheritance and the forces that affect this inheritance. We can predict the future of a child to the extent that we know and understand the forces that will be effective in his life.

The notion of causality puts new meaning into our view of the training of a child. The doctrine of development puts new meaning into our notion of the nature of a child. We can understand man only when we view him genetically, that is, in the light of his origin. We can understand a child only in the light of what his ancestors have been.

As these lines are being written, the greatest, the bloodiest war of history is in progress. Men are killing men by thousands and hundreds of thousands. How can we explain such actions? Observation of children shows that they are selfish, envious, and quarrelsome. They will fight and steal until they are taught not to do such things. How can we understand this? There is no way of understanding such actions until we come to see that the children and men of to-day are such as they are because of their ancestors. It has been only a few generations, relatively speaking, since our ancestors were naked savages, killing their enemies and eating their enemies’ bodies. The civilized life of our ancestors covers a period of only a few hundred years. The pre-civilized life of our ancestors goes back probably thousands and thousands of years. In the relatively short period of civilization, our real, original nature has been little changed, perhaps none at all. The modern man is, at heart, the same old man of the woods.

The improvements of civilization form what is called a social heritage, which must be impressed upon the original nature of each individual in order to have any effect. Every child has to learn to speak, to write, to dress, to eat with knife and fork; he must learn the various social customs, and to act morally as older people dictate. The child is by nature bad, in the sense that the nature which he inherits from the past fits him better for the original kind of life which man used to live than it does for the kind of life which we are trying to live now. This view makes us see that training a child is, in a very true sense, making him over again. The child must be trained to subdue and control his original impulses. Habits and ideals that will be suitable for life in civilized society must be built up. The doctrine of the Bible in regard to the original nature of man being sinful, and the necessity of regeneration, is fundamentally correct. But this regeneration is not so much a sudden process as it is the result of long and patient building-up of habits and ideals.

One should not despair of this view of child-life. Neither should one use it as an excuse for being bad, or for neglecting the training of children. On the contrary, taking the genetic view of childhood should give us certain advantages. It makes us see more clearly the necessity of training. Every child must be trained, or he will remain very much a savage. In the absence of training, all children are much alike, and all alike bad from our present point of view. The chief differences in children in politeness and manners generally, in morals, in industry, etc., are due, in the main, to differences in training. It is a great help merely to know how difficult the task of training is, and that training there must be if we are to have a civilized child. We must take thought and plan for the education and training of our children. The task of education is in part one of changing human nature. This is no light task. It is one that requires, in the case of each child, some twenty years of hard, patient, persistent work.

Individual Development. Heredity is a corollary of evolution. Individual development is intimately related to racial development. Indeed, racial development would be impossible without heredity in the individual. The individual must carry on and transmit what the race hands down to him. This will be evident when we explain what heredity means.

By heredity we mean the likeness between parent and offspring. This likeness is a matter of form and structure as well as likeness of action or response. Animals and plants are like the parents in form and structure, and to a certain extent their responses are alike when the individuals are placed in the same situation. A robin is like the parent robins in size, shape, and color. It also hops like the parent birds, sings as they do, feeds as they do, builds a similar nest, etc. But the likeness in action is dependent upon likeness in structure. The young robin acts as does the old robin, because the nervous mechanism is the same, and therefore a similar stimulus brings about a similar response.

Most of the scientific work in heredity has been done in the study of the transmission of physical characteristics. The main facts of heredity are evident to everybody, but not many people realize how far-reaching is the principle of resemblance between parent and offspring. From horses we raise horses. From cows we raise cows. The children of human beings are human. Not only is this true, but the offspring of horses are of the same stock as the parents. Not only are the colts of the same stock as the parents, but they resemble the parents in small details. This is also true of human beings. We expect a child to be not only of the same race as the parents, but to have family resemblances to the parents—the same color of hair, the same shape of head, the same kind of nose, the same color of eyes, and to have such resemblances as moles in the same places on the skin, etc. A very little investigation reveals likenesses between parent and offspring which we may not have expected before.

However, if we start out to hunt for facts of heredity, we shall perhaps be as much impressed by differences between parent and child as we shall by the resemblances. In the first place, every child has two parents, and it is often impossible to resemble both. One cannot, for example, be both short and tall; one cannot be both fair and dark; one cannot be both slender and heavy; one cannot have both brown eyes and blue. In some cases, the child resembles one parent and not the other. In other cases, the child looks somewhat like both parents but not exactly like either. If one parent is white and the other black, the child is neither as white as the one parent nor as black as the other.

The parents of a child are themselves different, but there are four grandparents, and each of them different from the others. There are eight great grandparents, and all of them different. If we go back only seven generations, covering a period of perhaps only a hundred and fifty years, we have one hundred and twenty-eight ancestors. If we go back ten generations, we have over a