Naturally, these incidents are not told in order to encourage methods of teaching that appeal to the sensational, the extraordinary, or the incomprehensible. They are told, however, to enforce the point that the familiar and the near do not excite or repay thought on their own account, but only as they are adjusted to mastering the strange and remote. It is a commonplace of psychology that we do not attend to the old, nor consciously mind that to which we are thoroughly accustomed. For this, there is good reason: to devote attention to the old, when new circumstances are constantly arising to which we should adjust ourselves, would be wasteful and dangerous. Thought must be reserved for the new, the precarious, the problematic. Hence the mental constraint, the sense of being lost, that comes to pupils when they are invited to turn their thoughts upon that with which they are already familiar. The old, the near, the accustomed, is not that _to_ which but that _with_ which we attend; it does not furnish the material of a problem, but of its solution. [Sidenote: which, in turn, can be given only through the old] The last sentence has brought us to the balancing of new and old, of the far and that close by, involved in reflection. The more remote supplies the stimulus and the motive; the nearer at hand furnishes the point of approach and the available resources. This principle may also be stated in this form: the best thinking occurs when the easy and the difficult are duly proportioned to each other. The easy and the familiar are equivalents, as are the strange and the difficult. Too much that is easy gives no ground for inquiry; too much of the hard renders inquiry hopeless. [Sidenote: The given and the suggested]