“Mr. Old: What gave me the opinion that the Devachan had some particular form and a place corresponding to its state was this. I think on page 235 {157}, Volume 1, where those tablets are given and the scheme of the different schools of thought in the East, it says: Upadhi is a basis and in a corresponding system of philosophy it is translated by the word {kosha}, which means a sheath. That word is very confounding, especially when we see that opposite Manas. Thus: one of the Devachanic principles is put [ ], or [ ], causal basis or sheath. You see, that is what gives one an incorrect opinion.
Mr. B. Keightley: Are not you confusing the idea of basis with the idea of form? They are not the same. For instance, the water you may consider the basis of something, but you could not say it has a form, per se.
Mme. Blavatsky: You consider gas the basis of something.
Mr. B. Keightley: Upadhi and form are not the same things.
Mr. Old: Has this Monad a diffused consciousness into the whole universal Devachan: Has it a locus? Has it a distinct place? Has it a limitation?
Mme. Blavatsky: It has not. Consciousness has no limitation.
Mr. B. Keightley: How can it have, when three belong to the Arupa world?
Mme. Blavatsky: Of which two are nothing.
Mr. B. Keightley: I was quoting The Secret Doctrine.
Mme. Blavatsky: You take the three systems of philosophy {in The Secret Doctrine, I:157}, one of which shows what the Theosophists give, one what the [ ] {Taraka Raja Yoga} give, and the other what the Vedantins give; it is not all that it corresponds.
It corresponds to one as a sheath, and the other does not. It is only our [ ], or the occult system, because that is a thing which is confined to the three principles, and we are dividing it into seven principles, because it is a great deal easier to explain.
The Vedantins have got five sheaths and the sixth, the Atma and the Buddhi, of which they don’t speak at {all}, because what they mean by [ ] does not mean at all the Buddhi, but simply the astral form.”
H. P. Blavatsky
The Mark Of God: Understanding Your "I AM Presence" 