In the foregoing chapters I have tried to show that there are, scattered here and there over the field of Psychic Research, sufficient indications to warrant our adopting, as a tentative working hypothesis, the idea that four-dimensional space is a reality and that the Individual consciousness is capable of functioning in a four-dimensional vehicle quite apart from the three-dimensional physical body.
I hope that I have made it quite clear that in my opinion the two vehicles are entirely separate and independent, and that I do not regard the three-dimensional body as being a mere section of a four-dimensional whole.
I propose in this chapter to consider in some detail the question of the nature of the connection which must perforce exist between the two vehicles.
We know that there must be some form of connection because impressions which are received by the three-dimensional sense organs are transmitted to the conscious Ego, which is, ex hypothesi, embodied in the four-dimensional vehicle.
Furthermore it is clear that the connection can be interrupted with comparative ease, since in sleep, anæsthesia, and analogous conditions, the conscious Ego does not receive these impressions although the sense organs may still be subject to stimuli to a greater or less degree.
We are not, of course, able to draw detailed conclusions as to the precise nature of this connection by the exercise of pure deductive reason.
But I think that my readers will agree with me that the first and most obvious place to look for it will be in the realm of the nervous system.
Further we may safely say that, assuming the hypothesis we are considering to be correct, the sense impression must, at some stage in its transmission, be deflected, so to speak, out of three space into four space.
In order for this to happen it is necessary that some part of the transmitting mechanism should be capable of producing this deflection and it is reasonable to suppose that a substance or mechanism specially differentiated for the purpose of deflecting impressions in this manner out of three space into four space, will be distinguished by an abnormal four-dimensional complexity as compared with ordinary matter, which, as we have already seen, probably possesses a very slight four-dimensional extension.
As a result of this abnormal four-dimensional complexity it is to be anticipated that the part of the transmitting mechanism concerned will possess characteristics sufficient to differentiate it from ordinary matter.