Out of the subject-matter, whether rich or scanty, important or trivial, of present experience issue suggestions, ideas, beliefs as to what is not yet given. The function of suggestion is not one that can be produced by teaching; while it may be modified for better or worse by conditions, it cannot be destroyed. Many a child has tried his best to see if he could not "stop thinking," but the flow of suggestions goes on in spite of our will, quite as surely as "our bodies feel, where'er they be, against or with our will." Primarily, naturally, it is not we who think, in any actively responsible sense; thinking is rather something that happens in us. Only so far as one has acquired control of the method in which the function of suggestion occurs and has accepted responsibility for its consequences, can one truthfully say, "_I_ think so and so." [Sidenote: The dimensions of suggestion:] [Sidenote: (_a_) ease] The function of suggestion has a variety of aspects (or dimensions as we may term them), varying in different persons, both in themselves and in their mode of combination. These dimensions are ease or promptness, extent or variety, and depth or persistence. (_a_) The common classification of persons into the dull and the bright is made primarily on the basis of the readiness or facility with which suggestions follow upon the presentation of objects and upon the happening of events. As the metaphor of dull and bright implies, some minds are impervious, or else they absorb passively. Everything presented is lost in a drab monotony that gives nothing back. But others reflect, or give back in varied lights, all that strikes upon them. The dull make no response; the bright flash back the fact with a changed quality. An inert or stupid mind requires a heavy jolt or an intense shock to move it to suggestion; the bright mind is quick, is alert to react with interpretation and suggestion of consequences to follow. Yet the teacher is not entitled to assume stupidity or even dullness merely because of irresponsiveness to school subjects or to a lesson as presented by text-book or teacher. The pupil labeled hopeless may react in quick and lively fashion when the thing-in-hand seems to him worth while, as some out-of-school sport or social affair. Indeed, the school subject might move him, were it set in a different context and treated by a different method. A boy dull in geometry may prove quick enough when he takes up the subject in connection with manual training; the girl who seems inaccessible to historical facts may respond promptly when it is a question of judging the character and deeds of people of her acquaintance or of fiction. Barring physical defect or disease, slowness and dullness in _all_ directions are comparatively rare. [Sidenote: (_b_) range]