The mystic sees on the abstract plane one or other element predominating at a certain time, either ether, air, fire, water or earth. Every element in the finer forces of life is rendered intelligible by the direction of its activity and color; and the various forms of light show its different rates of activity. For instance the feeling of humor develops into greater humor, and sadness into a deeper sorrow, and so it is with the imagination: every pleasant thought develops pleasure and expands into still pleasanter thought, and every disagreeable imagination grows and becomes more intense. Again, on the physical plane we not only see men dwelling together in cities and villages, but even beasts and birds living in flocks and herds; coal is found in the coal-mine, and gold in the gold-mine; the forest contains thousands of trees, where as the desert holds not a single one. All this proves the power of affinity which collects and groups the kindred atoms, and makes of them numerous forms, there by creating an illusion before the eye of man who thus forgets the one source in the manifestation of variety. (Hazrat Inayat Khan)