There is a tremendous value to breathing in and out.
We do it every day but we're not there for it. It just happens.
Now, you may think to yourself, that's the way it's supposed to be- after all, the whole organism is arranged so that this takes place without us having to supervise it.
Good thing, too- because the way we usually work, if we had to remember to breathe in and out, well, some damn thing would happen and it would go right out of our mind and we'd forget to do it and we'd die.
Fortunately there's a center in us that understands this and keeps it going- just like it digests our food. We could never manage work that detailed or that fine with our ordinary mind, so we have a different mind that does it for us.
But in the matter of breathing, there is something else going on. This is an activity where the participation of the attention can effect a remarkable change in the relationship we have to our bodies, and what they can take in.
Air is saturated with prana. Yoga schools, knowing this, have all kinds of esoteric exercises designed to increase the intake and uptake of prana.
And just what is prana? Technically- that is, theoretically- speaking, it forms the physical bridge between the astral and planetary bodies. That's why the esoteric yoga schools take such a great interest in it.
In the larger scheme of things, however, we can only say with certainty that it's a mystery. Gurdjieff would have called it a higher substance. It may well be the same manna from heaven that fed Moses' tribe in the wilderness. Whatever it is called, however it is explained, this much is certain: it's a subtle food that supports our experience of being. In sufficient quantity it can transform our inner life, putting us into touch with a joyful support for our daily effort. It can truly bring about an experience of what Christ called "The peace of the Lord which passeth all understanding."
People just don't know prana is there. If everyone was aware of how ingesting prana can feed the joyfulness of daily life, we'd all be trying to do that. Unfortunately, it's generally inaccessible to us because we are not arranged properly inside. The parts that can take it in don't work well. The parts that can bring it to places where it can be of use don't work well. The parts that store it don't work well. We can get chemical substances that substitute for it- nicotine is one- but they are temporary, addicitve, immediately draining and ultimately posionous.
Yoga (if it's practised in its esoteric form, as opposed to a glorfied form of exercise) has a whole set of techniques for repairing the organism's prana mechanism. Unfortunately it takes a lifetime- or perhaps numbers of them- for any of this to succeed in most people.
Gurdjieff was better informed than most Yogis, and, I think, had a fairly simple and very practical method for bringing people into more direct contact with this work. It did not involve complicated physical exercises (although, to be perfectly fair, he had them, in the form of his movements.) No, Gurdjieff's method was this:
Put the attention at the place where impressions enter the body.
You can read more about this in P.D. Ouspensky's "In Search Of The Miraculous," pages 188-189. (Harcourt Brace edition,.) If you want to understand just how comprehensive Gurdjieff's understanding of this entire matter is, read the whole chapter. Your eyes may glaze over, true, but I can guarantee you'll never think about your body the same way again.
Now, Gurdjieff spoke of impressions in this chapter in rather general terms, but based on a number of years of study I firmly believe he was pointing Ouspensky (and the rest of us) towards a very specific kind of impression: that is, the impression of air entering the body. He repeatedly draws chalk circles around the whole subject which point the reader in that direction.
There is a long, deep and joyful work involved in exploring this, and this isn't the place to expound on it.
It's enough to say that those who embark on a serious study of this question may discover things about air and breathing that suprise and astonish.