A rabbinical principle Neville adopts as his own rule of evidence, and his standing answer to the scientists and philosophers who ask him to bring his experiences down to this world and account for them in terms of its structure. He says plainly that he cannot: he is not a physicist, not a scientist and not a philosopher, and he can present nothing known to science to support his claim. What he can do is what the unknown author of Hebrews did - rest the entire argument on scripture, quoting or referring to it in every chapter - because according to the principle, what is not written in scripture is nonexistent. It works in both directions, which is why he keeps it: it is a limit he accepts, in that he will not argue his experience on the world's terms, and a licence he takes, in that he will not accept any account of the experience that scripture does not carry. His one concession is the sentence he falls back on instead of an explanation: I can only tell what has happened to me.