It is, in fact, a game where your ingenuity and moral power are brought into the field, in opposition to the evil tendencies of the hearts which are under your influence.

You will notice the success or the failure of the means you may put into operation with all the interest with which the experimental philosopher observes the curious processes he guides, though your interest may be much purer and higher, for he works upon matter, but you are experimenting upon mind.
Remember, then, as for the first time you take your new station at the head of your school, that it is not your duty simply to watch with an eagle eye for those accidental instances of transgression which may chance to fall under your notice.

You are to look over the whole ground.
You are to make yourself acquainted, as soon as possible, with the classes of character and classes of faults which may prevail in your dominions, and to form deliberate and well-digested plans for improving the one and correcting the other.
And this is to be the course pursued not only with great delinquencies, such as those to which I have already alluded, but to every little transgression against the rules of order and propriety.

You can correct them far more easily and pleasantly in the mass than in detail.
To illustrate this principle by another case.

A teacher, who takes the course I am condemning, approaches the seat of one of his pupils, and asks to see one of his books.