I have neither the knowledge nor the temerity to embark upon a discussion of the point from the metaphysical point of view and all I wish to do is to show that I am aware that all our ideas regarding space are liable to be modified at the hands of the philosophers and that I have no desire to minimise the importance of their contributions. On the contrary I think it probable that these may prove to be of the utmost value. They may, for instance, by interpreting spatial experience in terms of consciousness, throw light on the very considerable difficulty to which I drew attention on page 48. But I submit that for the present purpose we can legitimately disregard the whole thing. It may well be that the change in passing from our present state of consciousness to that which I have described as consciousness in four dimensions is subjective rather than objective, that the change would be in our consciousness rather than in spatial conditions. But whatever may be the real nature of our three-dimensional space from the strictly academic point of view we can and habitually do treat it as an objective reality and I think it fair to claim an equal licence in dealing with four-dimensional space. Pure consciousness is an elusive thing to handle and if we find evidence to the effect, for example, that the state of consciousness in which we exist when separated from the body can be accurately represented by the higher space hypothesis, then surely we had better say that it is existence in four-dimensional space and have done with it, just as we say that our normal existence is existence in three dimensional space. After all the whole matter is one of "relativity" so to speak. The final effect with which we are concerned is the reaction of reality on our minds and, just as we can in dynamics reduce any one member of a system to rest and treat all motions as relative to that so here it makes no practical difference whether it is our mind or reality which changes provided that the changed relation between them is correctly expressed. CHAPTER V VITALITY AND WILL Another and particularly happy illustration of the way in which the higher space concepts enable one to solve awkward dilemmas is to be found in the problems of Vitality and Will. Readers who are interested in these topics would do well to refer to Mr. Hereward Carrington's "Problems of Psychical Research" or to his "Vitality, Fasting, and Nutrition."