mind without an admixture of conventions, of what may be called fictions. These fictions have to be introduced, used, and then withdrawn. It would be impossible to teach even so straightforward a subject as mathematics without the temporary use of statements which are not true to the nature of things. The history of a child who is learning mathematics, like that of human thought, is very much a record of alternate introduction of convenient fictions and subsequent analysis of their true Nature. A class, like a public, tends at times to become groovy and mechanical; to mistake the accidental for the essential; to treat necessary aids to learning as if they were actual truths; to lose sight of the relative importance of various kinds of information. A class in Botany tends to forget that classification and terminology are not so much part of the life of plants as circulation and fertilization; a class in Analytical Geometry forgets that the co-ordinates are no part of a curve. Just so, the reading public forgot, till Charles Darwin woke it up, that intermittence is no necessary part of Creative Action; although it is convenient for man, for purposes of classification, to imagine a series of intermittent acts. A student tends to such forgetfulness in proportion as he becomes mechanical in his work; the genius of a teacher is very much shown by the manner in which he contrives to arouse the interest and correct the errors of a class which is becoming too mechanical.
Theorists in education sometimes imagine that a good teacher should not allow the work of his class to become mechanical at all. A year or two of practical work in a school (especially with Examinations looming ahead)
