"For it is the Buddhi-Manas which is called the Causal Body, (the United 5th and 6th Principles) and which is Consciousness, that connects it with every personality it inhabits on earth." (Key to Theosophy, p. 121)

"Speaking of Manas, the 'Causal Body,' we may call it - when connecting it with the Buddhic radiance - the 'HIGHER EGO,' never the 'Higher Self."' (Key to Theosophy, p. 174)

"... you have not yet grasped very firmly the difference between the sixth and seventh and the fifth, or the immortal and the astral or personal 'Monads = Egos.' ...the 'real Ego inheres in the higher principles which are reincarnated' periodically every one, two, or three or more thousands of years. But the immortal Ego the 'Individual Monad,' is not the personal monad which is the 5th ..." (Mahatma Letters, p. 183, #24B)

Neo-Theosophy:

"The ego dwells in a causal body, and when he takes upon himself in addition a mental and an astral body, the operation involves the actual entangling of a portion of the matter of his causal body with the matter of those lower astral and mental types." ( C.W. Leadbeater, The Inner Life I, pp. 205-6)

"When the Thinker has consumed in the mental body all the fruits belonging to it of his earthly life, he shakes it off and dwells unencumbered in his own place. All the mental faculties which express themselves on the lower levels are drawn within the causal body - with the germs of the passional life that were drawn into the mental body when it lef t the astral shell to disintegrate in Kamaloka - and these become latent for a time, lying within the causal body, forces which remain concealed for lack of material in which to manifest. The mental body, the last of the temporary vestures of the true man, disintegrates, and its materials return to the general matter of the mental plane, whence they were drawn when the Thinker last descended into incarnation. Thus the causal body alone remains, the receptacle and treasure house of all that has been assimilated from the life that is over." (Annie Besant, Ancient Wisdom, p. 161)

"0nce again, there begins the process of involution, and now of the Ego who lives in the causal body. When the Ego descends into incarnation, he undergoes limitation plane by plane, as he makes successively the mental, astral and physical bodies." ( C . Jinarajadasa, First Principles of Theosophy, p. 197) [16]