According to Pope, the proper study of mankind is man. How shallow, how harmful such a dictum! Contrast Kant's deeper insight. "Two things fill me with awe—the starry heaven without, and the moral law within." That famous apophthegm leads us nearer to the saving truth. For it contemplates man, not in his isolation, but as placed in a marvellous physical environment: to understand one you must understand the other also. Add the thought expressed in the fundamental principle of Nature Mysticism—the thought that nature is spiritually akin to ourselves—and we see that the proper study of mankind is human nature as a part of a living whole.
But the nature-mystic is not content to "study." He desires to hold communion with the spirit and the life which he feels and knows to be manifested in external nature. For him there is no such thing as "brute" matter, nor even such a thing as "mere" beauty. He hears deep calling unto deep—the life within to the life without—and he responds.