We have already seen that the mind and the body are associated in a copartnership in which each is an indispensable and active member. We have seen that the body gets its dignity and worth from its relation with the mind, and that the mind is dependent on the body for the crude material of its thought, and also for the carrying out of its mandates in securing adaptation to our environment. We have seen as a corollary of these facts that the efficiency of both mind and body is conditioned by the manner in which each carries out its share of the mutual activities. Let us see something more of this interrelation. 1. INTER-RELATION OF IMPRESSION AND EXPRESSION _No impression without corresponding expression_ has become a maxim in both physiology and psychology. Inner life implies self-expression in external activities. The stream of impressions pouring in upon us hourly from our environment must have means of expression if development is to follow. We cannot be passive recipients, but must be active participants in the educational process. We must not only be able to _know_ and _feel_, but to _do_. [Illustration: FIG. 20] THE MANY SOURCES OF IMPRESSIONS.--The nature of the impressions which come to us and how they all lead on toward ultimate expression is shown in the accompanying diagram (Fig. 20). Our material environment is thrusting impressions upon us every moment of our life; also, the material objects with which we deal have become so saturated with social values that each comes to us with a double significance, and what an object _means_ often stands for more than what it _is_. From the lives of people with whom we daily mingle; from the wider circle whose lives do not immediately touch ours, but who are interpreted to us by the press, by history and literature; from the social institutions into which have gone the lives of millions, and of which our lives form a part, there come to us constantly a flood of impressions whose influence cannot be measured. So likewise with religious impressions. God is all about us and within us. He speaks to us from every nook and corner of nature, and communes with us through the still small voice from within, if we will but listen. The Bible, religious instruction, and the lives of good people are other sources of religious impressions constantly tending to mold our lives. The beautiful in nature, art, and human conduct constantly appeals to us in aessthetic impressions.