But all this is surely beyond children? By no means; every walk should quicken their enthusiasm for the things of nature, and their reverence for the priests of that temple; but occasion should be taken to mark the progressive advances of science, and the fact that the teaching of to-day may be the error of to-morrow, because new light may lead to new conclusions even from the facts already known. “Until quite lately, geologists thought ... they now think ... but they may find reason to think otherwise in the future.” To perceive that knowledge is _progressive_, and that the next “find” may always alter the bearings of what went before; that we are waiting, and may have very long to wait, for the last word; that science also is “revelation,” though we are not yet able fully to interpret what we know; and that ‘science’ herself contains the promise of great impetus to the spiritual life--to perceive these things is to be able to rejoice in all truth and to wait for final certainty. In another way we may endeavour to secure for the children that stability of mind which comes of self-knowledge. It is well that they should know so early, that they will seem to themselves always to have known, some of the laws of thought which govern their own minds. Let them know that, once an idea takes possession of them, it will pursue, so to speak, its own course, will establish its own place in the very substance of the brain, will draw its own train of ideas after it. One of the most fertile sources of youthful infidelity is the fact that thoughtful boys and girls are infinitely surprised when they come to notice the course of their own thoughts. They read a book or listen to talk with a tendency to what is to them “free-thought.” And then, the “fearful joy” of finding that their own thoughts begin with the thought they have heard, and go on and on to new and startling conclusions on the same lines! The mental stir of all this gives a delightful sense of power, and a sense of inevitableness and certainty too; for they do not intend or try to think this or that. It comes of itself; their reason, they believe, is acting independently of them, and how can they help assuming that what comes to them of itself, with an air of absolute certainty, must of necessity be right?