Sri Chinmoy: The subtle body is undoubtedly less dense than the physical body is. We really have three bodies. As we go deep within, these bodies become more subtle. Each person has what is called in Sanskrit sthula sharira, the physical body. Inside the physical there is another body, called sukshma sharira, the subtle body. Inside the subtle body is a third body, called karana sharira, the causal body.
Before the creation started — the creation that we see all around — Hiranyagarbha existed. Hiranyagarbha is a Sanskrit word that means golden womb ( Hiranya means gold and garbha means womb). Our physical eyes will never be able to see or feel this Hiranyagarbha, but it is there that the seed of creation originally germinated. From there the causal body came into existence.
In the causal body we have all qualities in seed form. In the subtle body we begin to get the manifestation of some things that are in the causal body. Finally, we get truth, reality, experiences and realisation in the gross physical body. The physical body is like a huge banyan tree which grows from a tiny seed. When we compare the physical body with the causal body, it is simply unbelievable. This is how the manifestation takes place: from the causal to the subtle, and from the subtle to the gross physical.
The causal body has the capacity to fulfil us, but it fulfils in the process of time, through the evolving wheel which we call evolution. With the causal body the journey begins, but it is with the physical body that we fulfil ourselves, and the universe fulfils itself, through the outer form.
By physical, we mean the outer consciousness of the universe. In its seed form this is karana sharira, but eventually this seed grows into the boundless universe. When it expands, it automatically reaches the highest. You may say that expansion and reaching the highest are two different things. But in God’s case, in the soul’s case, it is not like that. What touches the farthest corner of the universe is meaningless if it has not also reached the highest. God will never remain unfulfilled, and He will never allow us to remain unfulfilled either, so we are bound to reach the highest, farthest and deepest.