I can only say that the thing occurred; that it took place in precisely the manner I am about to narrate, and that I experienced it.

Yet, in justice to myself, I must open up some paths of preliminary approach toward the heart of the perplexity. And the first path is the realization that our world whatever it is, is certainly not the world as we see it! Regarding this I shall refer to a discourse upon “Gravitation and the Principle of Relativity,” by the distinguished English physicist, Dr. A. S. Eddington, which I had the pleasure of hearing him deliver before the Royal Institution. 10