The extent and power of this influence upon morals and manners, upon character, upon habits of speech and social bearing, are almost universally recognized. But the tendency to conceive of thought as an isolated faculty has often blinded teachers to the fact that this influence is just as real and pervasive in intellectual concerns. Teachers, as well as children, stick more or less to the main points, have more or less wooden and rigid methods of response, and display more or less intellectual curiosity about matters that come up. And every trait of this kind is an inevitable part of the teacher's method of teaching. Merely to accept without notice slipshod habits of speech, slovenly inferences, unimaginative and literal response, is to indorse these tendencies, and to ratify them into habits--and so it goes throughout the whole range of contact between teacher and student. In this complex and intricate field, two or three points may well be singled out for special notice. (_a_) Most persons are quite unaware of the distinguishing peculiarities of their own mental habit. They take their own mental operations for granted, and unconsciously make them the standard for judging the mental processes of others.[10] Hence there is a tendency to encourage everything in the pupil which agrees with this attitude, and to neglect or fail to understand whatever is incongruous with it. The prevalent overestimation of the value, for mind-training, of _theoretic_ subjects as compared with practical pursuits, is doubtless due partly to the fact that the teacher's calling tends to select those in whom the theoretic interest is specially strong and to repel those in whom executive abilities are marked. Teachers sifted out on this basis judge pupils and subjects by a like standard, encouraging an intellectual one-sidedness in those to whom it is naturally congenial, and repelling from study those in whom practical instincts are more urgent. [10] People who have _number-forms_--_i.e._ project number series into space and see them arranged in certain shapes--when asked why they have not mentioned the fact before, often reply that it never occurred to them; they supposed that everybody had the same power. [Sidenote: Exaggeration of direct personal influence]