In all these examples, the operation of mind which we have endeavoured to describe, is so exceedingly simple, that it is perhaps difficult to decide how much is the work of Nature, and how much belongs to the exercise here recommended. This at once proves its efficiency, as an imitation of her process, in following her in the path which she has here pointed out; and it at the same time recommends itself as strictly accordant with observation and experience. The teacher then, in order to render the knowledge he communicates useful, has only to do regularly and by system, that which, under the direction of Nature, every intelligent and enquiring mind in its best moments does for itself. Wherever a useful truth has been communicated in the school or family, or a moral act or precept has been read or announced, the question by the parent or the teacher, "What does that teach you?" will lead the pupil to reflection, not only on its nature, but on its use; and the ability to do so, as we shall afterwards see, may be acquired by almost any individual with ease. Regular training in this way, leads directly to habits of reflection and observation, which are of themselves of great value; but which, when found acting in connection with the desire and ability to turn every truth observed into a practical channel, become doubly estimable, and a public blessing. The pupil therefore ought early to be trained of himself to supplement the question, "What does this teach me?" or, "What can I learn from this?" to every circumstance or truth to which his attention is called; because the ability to answer it forms the chief, if not the only correct measure of a well educated person. In proof of this it is only necessary to remark, that as it is not the man who has accumulated the greatest amount of anatomical and surgical knowledge, but he who can make the best use of it, that is really the best surgeon; so it is not the man who has _acquired_ the largest portion of knowledge, but he who _can make the best use_ of the largest portion, that is the best scholar. Hence it is, that all the exercises in a child's education should have in view the practical use of what he learns, and of what he is to continue through life to learn, as the great end to which all his learning should be subservient.