The Satya Yuga as described in the Mahabharata Van Parv is described as an Age when all mankind lived naturally by truth. They were rooted in dharma so to say. There was no evil, no rich or poor, men did not live chasing desires and all that they needed was provided by the pressure of an inner will chastened by freedom from wants. There was no disease, hatred, vanity and fear because mankind lived in close direction and supervision of the gods in whom they had complete faith. The bull of dharma stood on all its four legs of austerity, purity, compassion and truth.
This description seems to be the Age when Gods of the Overmind, Swarloka governed mankind freely since mankind was open to their influence. Great though this was it was obviously not yet the perfect Age else it would not have degenerated. This degeneration of the Age of Gold took place through the removal of each of the four legs of Dharma as it is called. But a deeper truth is that while the operating system in Satya yuga was primarily the spiritual consciousness, it was at the expense of the mental, vital and the physical layers of our being. It was an age when the spiritual side of man was prominent but his other aspects were not fully developed. The result was an incompleteness of human evolution. Hence the decline began. In Treta there was the stress on the mind, whereas in Dwapara on the heroic vital. In Kaliyuga it is on matter. It is also likely that this ideal state was maintained by the kings and the sages who commanded great respect during that period. The rest of humanity may not have been so evolved but its tendencies remained under check as those who ruled and governed were godlike beings.
The fact that it declined is itself the sign of an imperfection that began to show up. This is the problem with the Overmind Gods that mighty and wise though they are, they do not yet have the key to the Divine Perfection of man. They can build a godlike humanity and not a divinised one. the difference though subtle is important. A godlike humanity has the possibility of error and it is largely a higher humanity in terms of its inner consciousness. True they lived long but we do not see much creative impulsion during this typal early humanity.
Mankind has since then moved forward. It has lost its intuitive spiritual consciousness that was more of a gift of the gods and from that perspective it is a fall. But in terms of overall progress, it has recovered grounds on the development of mind and the creative impulsion of life along with a tremendous growth in the understanding of material existence. The new humanity or the divine superhumanity of the future will integrate these later developments and hence will be much more complete and richer in its outward details. But also inwardly with the coming of the Supermind it would go beyond the gods and discover what they missed, the God within us as well as the God secret in matter and in every cell of our complex existence. The intuitive mind will be uplifted and its intuitive rays touch many areas of human activity. With the supermind established fully in earthly life, the need for decline and with it of an eventual pralaya would be gone. It will be a far more conscious and richer life inwardly and outwardly, a divinised life in which disease, death and evil and suffering will become not only unacceptable but impossible.
