Perhaps the most significant factor to be noted in this, and in similar cases, is that the successful response to a baffling situation is acquired, and that this acquisition remains a more or less permanent possession of the human or animal organism. Particularly important for the problem and practice of education is the mechanism by which these learned modes of behavior are acquired. For, to attain skill, knowledge, intellect, character, is to attain certain determinate habits of action, certain recurrent and stable ways of responding to a situation. The reason why the cat in the box ceased to perform the hundred and one random acts of clawing and biting, and after a number of trials got down to the immediately necessary business of turning the button was because it had learned that one thing only, out of the multitude of things it could do, would enable it to get out of the box and get its food. To say that it learned this is not to say that it consciously realized it; it means simply that when placed in such a situation again after having been placed in it a sufficient number of times, it will be set off to the turning of the button which gets it food, instead of biting bars and clawing at random--actions which merely serve further to frustrate its hunger. The animal has not consciously learned, but its nervous system has been mechanically directed. A large part of the education of humans as well as of animals consists precisely in the modification of our original responses to situations by a trial-and-error discovery of ways of attaining satisfactory and avoiding annoying situations. Both animals and humans, when they have several times performed a certain act that brings satisfaction, tend, on the recurrence of a similar situation, to repeat that action immediately and to eliminate with successive repetitions almost all the other responses which are possible, but which are ineffective in the attainment of some specific satisfaction. The whole training imposed by civilization on the individual is based ultimately on this fundamental fact that human beings can be taught to modify their behavior, to change their original response to a situation in the light of the consequences that follow it. This means that while man's nature remains on the whole constant, its operations may be indefinitely varied by the results which follow the operation of any given instinct. The child has its original tendency to reach toward bright objects checked by the experience of putting its hand in the flame. Later his tendency to take all the food within reach may be checked by the looks of scorn which follow that manifestation of man's original greed, or the punishment and privation which are correlated with it. Through experience with punishment and reward, humans may be taught to do precisely the opposite of what would have been their original impulse in any given situation, just as the monkey reported by one experimenter may be taught to go to the top of his