charles webster leadbeater

After a rest there, he feels the desire to descend to a level where the undulations are
perceptible to him, in order that he may feel himself to be fully alive; so he repeats the process of descent into
denser matter, and assumes once more a mental, an astral and a physical body. As his previous bodies have all
disintegrated, each in its tarn, these new vehicles are entirely distinct from them, and thus it happens that in
his physical life he has no recollection whatever of other similar lives which have preceded it.
This development of the ego is the object of the whole process of materialization; he assumes those veils of
matter precisely because through them he is able to receive vibrations to which he can respond, so that his
latent faculties may thereby be unfolded. Though man descends from on high into these lower worlds, it is
only through that descent that a full cognizance of the higher worlds is developed in him. Full consciousness
in any given world involves the power to perceive and respond to all the undulations of that world: therefore
the ordinary man has not yet perfect consciousness at any level–not even in this physical world which he
thinks he knows.
—  Charles Webster Leadbeater, A Textbook of Theosophy