Ramana Maharshi About Causal,Subtle And Gross Bodies

Each one of us has his own experience, namely dreamless sleep. At that time we have neither the gross nor subtle body. The mind having completely subsided we sink at rest in total darkness,knowing nothing. When the mind rises again from this darkness, either dream or waking results. When we wake up from deep sleep, we remember our experience thus, ‘I slept happily and did not have any dream’.

That is, we know that we existed even in that state of seeming darkness in which
there was not even a dream. That dark state is called the causal body, We who know that we knew that we existed there, is the real ‘I’.

In deep sleep, the ego (ahankara – the mind in the form of attachments) is still alive in the very subtle form of tendencies (vasanas); it is this form which is that base and cause for the rising of the subtle and gross bodies, and therefore it is called the causal body. Even in death, it is in this causal body that we exist.

This causal body is not destroyed by the death of the gross body. The reason for
asserting that even this causal body is not ‘I’, is that we exist there to know even that state to be alien to us. There, our existence alone is real, and we cannot be the form (darkness or ignorance) which we assume there.

Just as we rejected the gross body of the waking state as ‘I am not this body’,
even though it appeared to be ‘I’, and just as for the same reason we rejected the subtle body of the dream state as ‘not I’, let us now also reject this causal body (darkness or ignorance) of deep sleep as ‘not I’, since it is only a form which comes on us and goes.

Therefore, having firmly eliminated all these three bodies as ‘not I, not I’, what then remains, that knowledge, the consciousness (chit) of our existence (sat), alone is ‘I’.

Source: The Path of Sri Ramana PART ONE The Jñana aspect of the teaching By Sri Sadhu Om