Question: What I want to say is manomaya, ānandamaya koṣas, all these koṣa(s)
The koṣa(s), what we call the concept of koṣa(s) is a later concept. First there are principles. Here Sri Krishna refers to seven principles; at a later stage they become manifest in human consciousness when these principles become more crystallised; crystallisation of these principles individually is the function of koṣa: koṣa is nothing but a body.
A purely physical body is the annamaya koṣa, then prāṇamaya koṣa is the praṇā body, Pranic body; then comes manomaya body, manomaya koṣa, the mental body. Now, most of us have only these three bodies, we have not yet formed the vijñānamaya: to form a vijñānamaya koṣa requires a lot of sādhāna, it is an existing body, it is not a koṣa, therefore it is not automatic in us. In the animals manomaya koṣa is not present, therefore mental faculties do not operate. As we move forward koṣa(s) are formed. Very few people can be said to have vijñānamaya koṣa, it is still to be formed and ānandamaya koṣa very few people, very rarely can it be developed, that is why we are not automatically ānandamaya.
If we had the koṣa, then the powers which are manifested in that koṣa become automatic. Even small children are mental because mental koṣa exists, therefore mental faculties begins to operate even in small children. Children may not know how to reason out like you and I can reason out things but the question how, why, what, these are mental questions these are automatic in the child. The child does not need to learn; these are automatic questions which are especially mental in character.
So, koṣa(s) are different from these seven principles. Principles exist everywhere but as koṣa(s) they have to be crystallised. In the human being only the three koṣa(s) have been crystallised: annamaya, praṇāmaya, manomaya. Then if you develop further by sādhāna, by great tapasyā, then vijñānamaya koṣa can be developed; then can be developed ānandamaya koṣa. Now, ānandamaya koṣa is still not the last, although in the Taittiriya Upanishad, it speaks only of ānandamaya koṣa as the top. But according to this knowledge it is still not the topmost, it is top but not the topmost; there can be citmaya koṣa, satmaya koṣa, but that means a tremendous developed consciousness of which we do not have even imagination. So, because in our human evolution ānandamaya koṣa is the rarest, therefore it has been regarded as topmost and once you attain into Ananda, others become also easier of access therefore they are not mentioned as koṣa(s).
In due course when the super-humanity will be born, these koṣa(s) will become much more crystallised and therefore manifest. So, this is the first principle of manifestation. Seven Rishis who symbolise seven principles of existence, because of these seven principles the whole world is manifested in the way it is manifested. This is one of the secrets of the manifestation of the world. Up till now this knowledge was not given to us; even when the supreme knowledge was given, the 9th chapter, this particular detail was not given. So Sri Krishna now adds it here to make integral knowledge really integral and complete.
Then Sri Krishna speaks of, catvāro manavastathā, (X, 6). Mere seven principles are not enough for explaining the world. In addition to seven principles in the world, there is a four fold character of the world: seven principles and four characters. They are as it were like a weaving of a garment; the world may be regarded as a garment of which seven principles and four characters when they are all woven together that gives a complete fabric of the world.
What are these four characters? These are given in the Rig Veda in the hymn of Purusha. There is a very special hymn where there is a sacrifice of Purusha: the supreme Lord gives Himself into Para Prakriti. This knowledge was given to us in the 7th chapter when Sri Krishna says: ‘I have not one nature; I have two natures’: Apara Prakriti, and Para Prakriti. So, the knowledge of Para Prakriti is given already in the seventh chapter. Now, in the hymn of creation, where there is a Purusha sacrifice, in the Rig Veda, the Purusha manifests the world by offering Himself wholly into the Para Prakriti as a result of which Para Prakriti begins to manifest. It means there is a constant relationship between the supreme Divine as Purusha and supreme Divine as Para Prakriti: it is the same Purusha, same Reality but having two faces as it were.