Savitri, Book II, The Book Of The Traveller Of The Worlds, Canto X, The Kingdoms And Godheads Of The Little Mind, Part 1
Even the highest paradise of life energies is not enough to hold the Traveller. Nothing can hold him until he reaches the Highest. He moves into the first, lowest plane of Mind where the development of Mind in our life in a body first begins. Throughout the worlds of Mind, Sri Aurobindo speaks of Mind’s development in terms of increasing light and decreasing darkness. First the Traveller meets a silver-grey expanse where dim and shifting rays divide Life’s energies from Mind’s poise. He travels on in the Physical Mind which receives only from the erring senses and admits only the physical, objective, the actual. Rays of light continue to come and Mind evolves slowly but surely.