Imagine a number of flat-headed drawing pins lying points upward on a flat surface. Taken collectively as a system they will have no rigidity. Now imagine a board pressed down on those points so that they penetrate into the board. The points and the board alike will be invisible to the two space beings inhabiting the surface and yet the drawing-pins, taken collectively as a system would have acquired rigidity. Deforming stresses would be resisted by cohesive forces operating outside the two space surface altogether. This analogy is, naturally, imperfect; but I think that it enables us to form some idea of the way in which the rigidity of the levitating structure might result from its being held together by binding forces operating outside our space. The only alternative is to suppose that the particles of which the structure is composed are rendered rigid by virtue of some peculiar motion of the ether of a nature entirely unknown to us and different from any type of ethereal motion with which we are at present acquainted. This is palpably unsatisfactory and has the grave defect, in an explanation, of failing even to begin to explain. In an article published in "Light," for July 14, 1917, I discussed this point in somewhat greater detail. This is all that I have to say with respect to the phenomena which are essentially "Psychical." In the next chapter I shall deal with two other applications of the theory to more general questions. FOOTNOTES: [Footnote 1: Far be it from me to suggest that these last-mentioned factors play no part in the phenomena. On the contrary, their effect is at least very considerable, and does much to obscure and complicate the work of interpretation.] [Footnote 2: NOTE.--The foregoing remarks on the subject of Dreams might be taken to imply an ignorance of the views inaugurated by Freud, and extended by Jung, Pfister, and others of the Psychoanalytic school. But I do not think that there is any fundamental contradiction involved. Even if, as this school tends to maintain, there is no dream without it's hidden and esoteric meaning, it is still perfectly legitimate to suppose that the _form_ which a dream takes may be determined by causes of the type which I have been discussing here. These would provide the raw material so to speak which would be worked up into the finished dream in accordance with Freudian principles.] [Footnote 3: Compare the recent work of Rutherford, Soddy, Le Bon and others.] [Footnote 4: "The Reality of Psychical Phenomena" (Watkins).] CHAPTER IV SOME OTHER POSSIBLE APPLICATIONS OF THE HYPOTHESIS In this chapter I propose to deal first with the questions of Time and prevision and in the next to show how the higher space ideas help us to clear up certain difficulties in connection with Vitality and Will.