A child,in growing up,may meet and learn from three different kinds of discipline.The first and most important is what we might call the Discipline of Nature or Reality.When he is trying to do something real,if he does the wrong thing or doesn't do the right one,he doesn't get the result he wants.If he doesn't pile one block right on top of another,or tries to build on a slanting serface,his tower falls down.If he hits the wrong key,he hears the wrong note.If he doesn't hit the nail squarely on the head,it bends,and he has to pull it out and start with another.If he doesn't measure properly what he is trying to build,it won't open,close,fit,standup,fly,float,whistle,or do whatever he wants it to do.If he closes his eyes when he swings,he doesn't hit the ball.A child meets this kind of discipline every time he tries to do something,which is why it is so important in school to give children more chances to do things,instead of just reading or listening to someone talk.This discipline is a great teacher.The learner never has to wait long for his answer;it usually comes quickly,often instantly.Also it is clear,and very often points toward the needed correction;from what happened he can not only see that what he did was wrong,but also why,and what he needs to do instead.Finally,and most important,he giver of the answer, call it Nature,is impersonal,impartial,and indifferent.She does not give opinions, or make judgments; She cannot be wheedled, bullied, oe fooled; she does not get angry or disappointed; she does not praise or blame; she does not remember past failures or hold grudges; with her one always gets a fresh start, this time is the one that counts.