In the earliest times, humanity lived in a state of perfect harmony. There was neither desire nor aversion among them; all were equal in form and lifespan, with no sense of inferiority or superiority. For thousands of years, people lived with a fixed span of life, free from suffering or calamity. Occasionally, in certain places and times, the earth itself reflected this fortune, being entirely peaceful and abundant. Yet, as the ages passed, the natural course of beings led to their decline and eventual destruction. Gradually, all the accomplishments and blessings of that era faded everywhere. When these were lost, people seemed to fall from the sky, losing their former glory. In those days, marvelous wish-fulfilling trees, known as 'house-trees,' arose in abundance. From these trees, all enjoyments flowed effortlessly to the people. At the dawn of the Tretā Yuga, they made their homes in these trees, living in contentment. But as time moved on, sudden passion began to stir within them. Month after month, with the changing seasons, desire arose again and again, and with it, the phenomenon of conception returned. As passion grew, the house-trees responded. On some trees, great branches fell upon others, and from the fruits of these trees, garments and ornaments were produced. Within the hollows of these trees, honey appeared, rich in fragrance, color, and taste—strong and unfermented. Sustained by this honey, people lived peacefully at the beginning of the Tretā Yuga. But in time, greed began to fill their hearts once more. Driven by a sense of ownership, they seized the trees for themselves. This misconduct caused even these great wish-fulfilling trees to wither and perish. With their loss, the pairs of opposites—cold and heat, hunger and thirst—arose among people. To protect themselves from these hardships, they began to build dwellings for the first time. Seeking refuge, they settled in deserts, fortresses, mountains, caves, and other strongholds—whether wooded, rocky, or near water. They also constructed artificial fortresses, measuring them with their own fingers, and established standards of measurement for practical tasks as before. The smallest unit was the paramāṇu, followed by a mote of dust, earth-dust, the tip of a hair, a nit, a louse, and then a barley-corn. Each unit was eight times the previous one. Eight barley-corns made an aṅgula, or finger-breadth; six aṅgulas made a pada, or foot; and a vitasti, or span, was twice that. Two vitastis made a hasta, or cubit, measured from the wrist to the fingertip. Four hastas made a bow’s length, a staff, and the measure for a nāḍikā, or water-clock. Two thousand bows made a gavyūti, and four gavyūtis made a yojana—thus did the wise establish the supreme reckoning for measurement. Of the four types of fortresses, three arose naturally, while the fourth—the artificial fortress—was built with great effort. Settlements took many forms: cities, small fortified towns, mortar-shaped settlements, branch-towns, and hamlets. Villages were arranged with cattle-pens and separate dwellings, protected by raised embankments and surrounded by moats. A city was to have a diameter of half a yojana, with a width one-eighth its length, sloping eastward or northward, and exits made of pure bamboo. A small fortified town was half that size, a hamlet a quarter, and a mortar-shaped settlement even smaller, measured by its end portion. A city or hamlet without walls or moats was called a kharvaṭa, while a branch-town was inhabited by ministers, vassals, and landholders. Villages were mostly home to prosperous Śūdras skilled in agriculture, situated amid fertile fields. Any other settlement, established for a specific purpose apart from these, was simply known as a residence. Hamlets were often lawless, without fields, and occupied by powerful men on foreign land, serving as refuges for those favored by the king. A ghoṣa was a place where cowherds lived with their herds, moving freely without marketplaces, their goods loaded on carts. Thus, having established cities and other settlements, people built dwellings for families, often in pairs. As before, houses were built near trees, inspired by memories of their ancient way of life. The branches of their homes spread in all directions, just as tree branches grow upward and downward. The branches that once belonged to wish-fulfilling trees became the timber for their new homes. After suffering mutual destruction and loss, people pondered new means of livelihood, for with the loss of honey, the wish-fulfilling trees were entirely gone. Distressed and overwhelmed by sorrow, afflicted by hunger and thirst, they faced great hardship. Then, at the dawn of the Treta age, fortune smiled upon them again. When all other means failed, abundant rain fell, collecting in low places and forming streams and channels. These waters, which once merely trickled to the earth, now gathered in abundance. From the union of earth and water, plants arose—fourteen kinds, both cultivated and wild—growing without being sown or plowed. Trees and shrubs bearing flowers and fruits according to the seasons appeared, and for the first time, medicinal plants emerged in the Treta age. Sustained by these medicinal plants, people survived. Yet, once more, desire and greed arose among them. Each person began to lay claim to rivers, fields, mountains, trees, shrubs, and medicinal plants, seizing what they could according to their own strength and means.