Imaginative vision is quite different from mere perception of an object, for it has no limits. Not only can imagination travel through infinite space, but also through infinite time; we can go backwards through the epochs, and have the vision of the earth as it was, with the creatures that inhabited it. To make it clear whether or not a child has understood, we should see whether he can form a vision of it within his mind, whether he has gone beyond the level of mere understanding... The secret of good teaching is to regard the child's intelligence as a fertile field in which seeds may be sown, to grow under the heat of flaming imagination. Our aim therefore is not merely to make the child understand, and still less to force him to memorize, but so to touch his imagination as to enthuse him to his inmost core.