There are a good many thoughtful men in educational circles, who are disposed to make little or nothing of heredity, and everything of training. There'll be more to say of their emphasis on training when we come to that talk. There is no doubt at all that some have over-emphasized the heredity side in their study of life.
All things should be kept in proportion. The common pendulum swing, first one extreme then the other, should be avoided. Heredity can be taught in an extreme way, that will produce in some a sort of morbid fatalism that checks all growth. That's bad, of course. But then it mustn't be left out, because it can't be. It won't stay out. It's in, and in to stay. Heredity supplies the stuff to be trained. But it can be studied in a purely practical way, and that is all that concerns us here.
The word "heredity" stands for all the influences that enter into the making of character before birth. And there is an intensely practical side to it for us who are past that line, because it concerns the making of our own character; and, even more, it concerns the making of the character of the lives that we are to bring.
It puts a man on his guard at once to know of evil or weak tendencies he may have inherited. Forewarned is forearmed. The man whose father had a strong appetite for intoxicants, not always controlled, knows at once that he must be far more cautious and stern with himself than one who has no such taint in his blood. He will wisely lean over backwards to avoid that which would have an easier task to grip and throw him, if it once got an opening.
If one's father has been an easy spender, unable to hold money in his fingers; or, has gone to the extreme of closeness in the use of his money, that will influence the child. But to know of the bent either way will help an earnest man to avoid the inherited tendency which he may find cropping out above the soil of his life, and it will help him, too, to avoid swinging to the very opposite extreme, as is so often done.
It helps greatly, to remember that the inheritance is a tendency only; nothing more. The child doesn't inherit a disease, though he may inherit a tendency toward it. The tendency of whatever sort may be very strong. Yet it is only a tendency in the beginning. So all inherited traits are tendencies, more or less strong.
The early atmosphere, and then the habit, and then greatest of all, the will, decide what shall become of that tendency. The tendency toward an evil thing can be gripped and choked if it is known. The tendency toward a good trait can be guarded, or carelessly weakened, or wilfully destroyed, or it can be built up.
At the same time it is an enormous advantage to the earnest, ambitious young man or young woman to know of strong, desirable traits and tendencies inherited. It gives an element of confidence in developing one's character in those directions; though care should be taken not to presume on heredity here. For the inherited tendency which makes a thing easier must be cultivated and schooled if it is to grow into real strength in its own right.