The etheric means that which is concerned with the sky, space. The astral means the minutest, the sukshma, the last one, the atomic, beyond which matter ceases to exist. For the mental there is no difficulty. For the spiritual too there is no difficulty. For the cosmic too.
Then you have the seventh, the nirvanic. It will be better to understand what nirvana means. Nirvana means total cessation, the absolute zero, not even the seed; everything has ceased. The word linguistically means the going out of the flame; the flame gone out, the light put off. You cannot ask where it has gone. It has just ceased to be.
Nirvana means the flame which has gone out. Now it is nowhere, or everywhere. It has no particular point of existence and no particular time-moment of existence. Now it is the space and the time. It is the existence or the non-existence; now it makes no difference. You can use both terms, because it is everywhere – it is everywhere or it is nowhere. To be somewhere it cannot be everywhere, and to be everywhere it cannot be somewhere. Nowhere and everywhere mean the same. For the seventh you can use nirvanic because there is no better word for it, and if you stay in your own experiences and they convey to you something parallel to it, then it becomes more easy. Because if you have not known anything, and you have only the words, vacant, empty, without any meaning…words have no meaning at all. Only experience has meaning.
And if there is experience behind the word, the word becomes meaningful – otherwise it is meaningless and absurd. It appears to have meaning even when there is no experience, but that is only an appearance – a linguistic fallacy. So when you have experienced something of it, then you can make that experience deeper, and there are methods that can be used on particular planes.
Begin from the physical, and then every further step is opened to you. The moment you work on the first, you have glimpses of the second. So begin from the physical. Be aware of it, aware every moment, moment to moment, and not only outwardly – because we can become aware of our own body as seen from the outside.
I see my hand. I can become aware of it as I have seen it from the outside, but there is an inner feeling of my hand when I close my eyes too. Now the hand is not seen but there is the feeling, the inner feeling of there being something. So don’t be aware of your body as seen from the outside. This cannot lead you inward. If you become aware of your body as seen from the outside, then you can never grow with it, because the inner feeling is quite different.
When you feel it from within, what it is to be inside the body… I can see a house from the outside, it is one thing; from the inside, it is something else. It is the same house but from the inside it is something else. And from inside…the great difference is that when you see it only from the outside you cannot know its secrets. You know only the outer boundaries; as it looks to others.