Breathing is only one of the many exercises through which we get to the real Pranayama. Pranayama means the control of Prana. The whole universe is composed of two materials, one of which they call Akasa It is the omnipresent, all penetrating existence. Every­thing that has form, everything that is the result of compounds, is evolved out of this Akasa.

It is the Akasa that becomes the air, that becomes the liquids, that becomes the solids; it is the Akasa that becomes the sun, the earth, the moon, the stars, the comets; it is the Akasa that becomes the body, the animal body, the plants, every form that we see, everything that can be sensed, everything that exists (Advaita).
It itself cannot be perceived; it is so subtle that it is beyond all ordinary perception; it can only be seen when it has become gross, has taken form. At the beginning of creation there is only this Akasa; at the end of the cycle the solids, the liquids, and the gases all melt into the Akasa again, and the next creation similarly proceeds out of this Akasa.

By what power is this Akasa manufactured into this universe?

By the power of Prana. Just as Akasa is the infinite omnipresent material of this universe, so is this Prana the infinite, omnipresent manifesting power of this universe. At the beginning and at the end of a cycle everything becomes Akasa, and all the forces that are in the universe resolve back into the Prana; in the next cycle. out of this Prana is evolved every­thing that we call energy, everything that we call force. It is the prana that is manifesting as motion; it is the prana that is manifesting as gravitation, as magnetism. 
It is the prana that is manifesting as the actions of the body, as the nerve currents, as thought force. From thought, down to the lowest physical force, everything is but the manifestation of Prana. The sum-total of all force in the universe, mental or physical, when resolved back to its original state, is called Prana. " 

When there was neither aught nor naught, when darkness was covering darkness, what existed then? That Akasa existed without motion." 

The physical motion of the prana was stopped, but it existed all the same. All the energies that are now displayed in the universe we know, by modern science, are unchange­able. The sum-total of the energies in the universe remains the same throughout, only, at the end of a cycle, these energies quiet down, become potential, and, at the beginning of the next cycle, they start up, strike upon the Akasa, and out of the Akasa evolve these various forms, and, as the Akasa changes, this Prana changes also into all these manifestations of energy. 

This opens to us the door to almost unlimited power. Suppose, for instance, one understood the Prd1_ta per­fectly, and could control it, what power on earth could there be that would not be his? He would be able to move the sun and stars out of their places, to control everything in the universe, from the atoms to the big­gest suns, because he would control the  prana. This is the end and aim of Pranayama. 

When the Yogi becomes perfect there will be nothing in nature not under his control. If he orders the gods to come, they will come at his bidding; if he asks the departed to come, they will come at his bidding. All the forces of nature will obey him as his slaves, and when the ignorant see these powers of the Yogi they call them miracles. One peculiarity of the mind is that it always inquires for the last possible generalisation, leaving the details to be worked out afterwards. 

The question is raised in the Vedas, "What is that, knowing which we shall know everything?" Thus, all books, and all philosophies that have been written, have been only to prove That by knowing which everything is known. If a man wants to know this universe bit by bit he must know every individual grain of sand, and that means infinite time for him; he cannot know all of them. 

Then how can knowledge be? 
How is it possible for a man to be all-knowing through particu­lars? 
The Yoga say that behind this particular mani­festation there is a generalization. Behind all particular.