At length the causes that carried the Ego into Devachan are exhausted, the experiences gathered have been wholly assimilated, and the Soul begins to feel again the thirst for sentient material life that can be gratified only on the physical plane. The greater the degree of spirituality reached, the purer and loftier the preceding earth-life, the longer the stay in Devachan, the world of spiritual, pure, and lofty effects. [I am here ignoring the special conditions surrounding one who is forcing his own evolution, and has entered on the Path that leads to Adeptship within a very limited number of lives.] The "average time [in Devachan] is from ten to fifteen centuries", H.P. Blavatsky tells us, and the fifteen centuries cycle is the one most plainly marked in history.[39] But in modern life this period has much shortened, in consequence of the greater attraction exercised by physical objects over the heart of man. Further, it must be remembered that the "average time" is not the time spent in Devachan by any person. If one person spends there 1000 years, and another fifty, the "average" is 525. The devachanic period is longer or shorter according to the type of life which preceded it; the more there was of spiritual, intellectual, and emotional activity of a lofty kind, the longer will be the gathering in of the harvest; the more there was of activity directed to selfish gain on earth, the shorter will be the devachanic period. When the experiences are assimilated, be the time long or short, the Ego is ready to return, and he brings back with him his now increased experience, and any further gains he may have made in Devachan along the lines of abstract thought; for, while in Devachan, In one sense we can acquire more knowledge; that is, we can develop further any faculty which we loved and strove after during life, provided it is concerned with abstract and ideal things, such as music, painting, poetry, &c.[40]