What has Pranayama to do with spiritualism? Spiritualism is also a manifestation of Pranayama. If it be true that the departed spirits exist, only we cannot see them, it is quite probable that there may be hundreds and millions of them about us we can neither see, feel, nor touch. We may be continually passing and repassing through their bodies, and they do not see or feel us. It is a circle within a circle, universe within universe. We have five senses, and we represent Prana in a certain state of vibration. All beings in the same state of vibration will see one another, but if there are beings who represent Prana in a higher state of vibration, they will not be seen. We may increase the intensity of a light until we cannot see it at all, but there may be beings with eyes so powerful that they can see such light. Again, if its vibrations are very low, we do not see a light, but there are animals that may see it, as cats and owls. Our range of vision is only one plane of the vibrations of this Prana. Take this atmosphere, for instance; it is piled up layer on layer, but the layers nearer to the earth are denser than those above, and as you go higher the atmosphere becomes finer and finer. Or take the case of the ocean; as you go deeper and deeper the pressure of the water increases, and animals which live at the bottom of the sea can never come up, or they will be broken into pieces.