We may some day have a valid psychology of religion, though we are far from it yet: but when we do, it will only be true within its own system of reference. It will deal with the fact of the spiritual life from one side only. And as a discussion of the senses and their experience explains nothing about the universe by which these senses are impressed, so all discussion of spiritual faculty and experience remains within the human radius and neither invalidates nor accounts for the spiritual world. When the psychologist has finished telling us all that he knows about the rules which govern our mental life, and how to run it best, he is still left face to face with the mystery of that life, and of that human power of surrender to Spiritual Reality which is the very essence of religion. Humility remains, therefore, not only the most becoming but also the most scientific attitude for investigators in this field. We must, then, remember the inevitably symbolic nature of the language which we are compelled to use in our attempt to describe these experiences; and resist all temptation to confuse the handy series of labels with which psychology has furnished us, with the psychic unity to which they will be attached.
Perhaps the most fruitful of all our recent discoveries in the mental region will turn out to be that which is gradually revealing to us the extent and character of the unconscious mind; and the possibility of tapping its resources, bending its plastic shape to our own mould. It seems as though the laws of its being are at last beginning to be understood; giving a new content to the ancient command “Know thyself.” We are learning that psycho-therapy, which made such immense strides during the war, is merely one of the directions in which this knowledge may be used, and this control exercised by us. That regnancy of spirit over matter towards which all idealists must look, is by way of coming at least to a partial fulfilment in this control of the conscious over the unconscious, and thus over the bodily life. Such control is indeed an aspect of our human freedom, of the creative power which has been put into our hands. In all this religion must be interested: because, once more, it is the business of religion to regenerate the whole man and win him for Reality.