But a man by bare intellectuality can not cross the threshold of Svarga. The Devas reject the intruder. However much Trisanku might aspire to have the enjoyments of Svarga, and however great his intellect might be, he was not allowed to enter the coveted plane, without the passport of spirituality. Humanity had still to learn the proper means of securing life in Svarga. Poor and chance spiritual acquisitions give only a passing life in Svarga and that not of a superior character. So all the knowledge as to attaining Svarga life had to be revealed in time. The Rishis made great efforts to improve humanity by securing for them a prolonged existence in Svarga, most of all Rishi Visvâmitra, one of the seven sages of our Manvantara. Visvâmitra failed in his attempt to send Trisanku to Svarga. He then tried with his son Haris Chandra. It is said he advised the Râjâ to make a human sacrifice to Varuna. But we find the victim Sunah-sepha living after the sacrifice, under the name of Deva-rata, or one given up to the gods, and some of the Riks even were revealed to him. Haris Chandra succeeded in entering Svarga. That was a great victory for Rishi Visvâmitra. The Vedas were revealed to the Rishis and sacrifices came to be known. Nârada also helped the cause in another away. He related the beauty and the virtues of king Purûravas to the Devas in Svarga. Urvasi, the famous Deva nymph, hearing all that, became enamoured of the king. She had then, by the curse of some god, a human form. So she could keep company with the King. The king was enchanted by her beauty. When she left, he followed her advice and pleased the Gandharvas. The Gandharvas gave him the fire, with which the king could perform sacrifice. The fire became threefold. With one he could perform his duties to the Devas and go to Svarga Loka. With another, he could perform his duties to the Pitris. With the third fire, he could perform the duties of a house-holder. Thus sacrifices meant duties. And it is by the performance of duties that men can perform Vedic sacrifices and go to Svarga Loka.