The various kinds of habits which we have enumerated are alike in certain fundamental particulars. In all of them there is a definite situation followed by a definite response. One sees the switch and turns off the light; he sees the expression "nine times nine" and says "eighty-one"; he sees a lady he knows and tips his hat; in meeting a carriage on the road, he turns to the right; when he has to vote, he votes a certain ticket; when he has to report an occurrence, he tells it as it happened. There is, in every case, a definite situation followed by a definite response. Another characteristic is common to all the cases mentioned above, _i.e._ the response is acquired, it does not come at first. In every instance we might have learned to act differently. We could form the habit of always leaving the light burning; could just as easily say "nine times nine equals forty"; we could turn to the left; we could vote the Republican ticket. We can form bad moral habits as well as good ones, perhaps more easily. The point is, however, that we acquire definite ways of acting for the same situations, and these definite ways of acting are called habits. =Habit and Nerve-Path.= It has already been stated that a habit is a tendency toward a certain type of action in a certain situation. The basis of this tendency is in the nervous system. In order to understand it we must consider what the nervous system is like. Nerves terminate at one end in a sense organ and at the other end ultimately in a muscle. In Figure II, A is a sense organ, B a nerve going from the sense organ to the brain C. D, E, F, G, and H are motor nerves going from the brain to the muscles. Now, let us show from the diagram what organization means and what tendency means. At first when the child sees the expression "nine times nine," he does not say "eighty-one." The stimulus brings about no definite action. It is as likely to go out through E or F as through D. But suppose we can get the child to say "nine times nine equals eighty-one." We can write the expression on the blackboard and have the child look at it and say "nine times nine equals eighty-one." Suppose the act of saying "eighty-one" is brought about by the nerve-current going out through nerve-chain D. By repetition, we establish a bond. A stimulus of a particular kind comes through A, goes over B to C, and out over D, making muscles at M bring about a very definite action in saying "eighty-one." [Illustration: FIGURE II.--THE ORGANIZATION OF TENDENCIES]