Grace brings success. However, it is not the essential or fundamental thing; it is only the ornament and must therefore be used sparingly and only in little things. In the lower trigram of fire a yielding line comes between two strong lines and makes them beautiful, but the strong lines are the essential content and the weak line is the beautifying form. In the upper trigram of the mountain, the strong line takes the lead, so that here again the strong element must be regarded as the decisive factor. In nature we see in the sky the strong light of the sun; the life of the world depends on it. But this strong, essential thing is changed and given pleasing variety by the moon and the stars. In human affairs, aesthetic form comes into being when traditions exist that, strong and abiding like mountains, are made pleasing by a lucid beauty. By contemplating the forms existing in the heavens we come to understand time and its changing demands. Through contemplation of the forms existing in human society it becomes possible to shape the world.