The Vedic Rishis never attained to the supermind for the earth or perhaps did not even make the attempt. They tried to rise individually to the supramental plane, but they did not bring it down and make it a permanent part of the earth consciousness. Even there are verses of the Upanishad in which it is hinted that it is impossible to pass through the gates of the Sun (the symbol of the supermind) and yet retain an earthly body. It was because of this failure that the spiritual effort of India culminated in Mayavada. Our Yoga is a double movement of ascent and descent; one rises to higher and higher levels of consciousness, but at the same time one brings down their power not only into mind and life, but in the end even into the body. And the highest of these levels, the one at which it aims is the supermind. Only when that can be brought down is a divine transformation possible in the earth-consciousness.
Ref: Letters on Yoga Vol. II