Now it is the teacher's business to see that the onslaught of knowledge does not enfeeble. Between the two sides of knowledge, information and intelligence, he is to keep the balance true. While a boy is taking in facts, facts not allowed to be twisted by any fancy or carelessness, he is all the time to be made to feel that these facts offer him a field for critical and constructive action. If they leave him inactive, docile, and plodding, there is something wrong with the teaching. Facts are pernicious when they subjugate and do not quicken the mind that grasps them. Education should unfold us and truth together; and to enable it to do so the learner must never be allowed to sink into a mere recipient. He should be called on to think, to observe, to form his own judgments, even at the risk of error and crudity. Temporary one-sidedness and extravagance is not too high a price to pay for originality. And this development of personal vigor, emphasized in our day by the elective system and independent research, is the great aim of education. It should affect the lower ranges of study as truly as the higher. The mere contemplation of truth is always a deadening affair. Many a dull class in school and college would come to life if simply given something to do. Until the mind reacts for itself on what it receives, its education is hardly begun. The teacher who leads it so to react may be truly called "productive," productive of human beings. The noble word has recently become Germanized and corrupted, and is now hardly more than a piece of educational slang. According to the judgments of to-day a teacher may be unimaginative, pedantic, dull, and may make his students no less so; he will still deserve a crown of wild olive as a "productive" man if he neglects his classroom for the printing press. But this is to put first things second and second things first. He who is original and fecund, and knows how to beget a similar spirit in his students, will naturally wish to express himself beyond his classroom. By snatching the fragments of time which his arduous work allows, he may accomplish much worthy writing and probably increase too his worth for his college, his students, and himself. But the business of book-making is, after all, collateral with us teachers. Not for this are we employed, desirable though it is for showing the kind of mind we bear. Many of my most productive colleagues have printed little or nothing, though they have left a deep mark on the life and science of our time. I would encourage publication. It keeps the solitary student healthy, enables him to find his place among his fellows, and more distinctly to estimate the contributions he is making to his subject. But let him never neglect his proper work for that which must always have in it an element of advertising.