This pronounced assertion of Rāja within all Nature is betrayed by outward signs and symptoms. Distinct changes are observable in the thoughts and actions of men, while there is decrease in the wild natural growth and products of edible fruits, roots and corn. These main features of change mark the end of Satya Yuga (Golden Age) and the beginning of the Tretā Yuga (Silver Age). From natural all-absorbing, inward concentration upon the basic principle of the Universe—Love—and drawing absolute never-failing happiness therefrom, most people now begin to look outwards for happiness, trying to draw it from the enjoyment of material objects. A small portion, however, still retains the same inward look and enjoys the primeval ecstatic condition of the mind. These still live in the Tree of Life. But those who look outwards and try to draw happiness from without, eat tor the first time of the fruit of the Tree of Knowledge, as indicated by the figurative language of the Christian Bible. So long as they do not look outwards, they do not know of material pleasure, pleasure which is mixed with pain, Rājasic pleasure, pleasure which lasts for only a short while, pleasure which has reaction of pain or cessation. This knowledge of material pleasure and hankering for securing them is the fall of humanity. The cause of this outward-looking is to be traced to the assertion of the Cardinal Attribute of Activity (Rāja) within Nature rather than to any fault in her products themselves. Predominant Sattwa (Illumination) maintains the harmony in the mind induced by calm concentration upon one object and that object a steady, Changeless one. Predominant Rāja (Activity) destroys this harmony and calmness by making the mind active with thoughts of many objects. This state of activity itself turns the point of the mind's ken outwards and disturbs its harmony. The mind is active only when it has to deal with the impressions of more than one object. When the surface of a mirror is turned towards the sky, it reflects only that one blue sky. When it is turned towards the earth it reflects many objects. Such is the case with the mirror of the mind. When it is turned inwards to the soul, it reflects its one all-pervading, colorless radiance and is therefore tranquil and happy. When it is turned outwards, it reflects the many-colored objects and is disturbed by their conflicting attributes.