"The progress of human knowledge depends on maintaining that touch of scepticism even about the most "unquestionable" truths. A century ago, Darwin's theory of evolution by natural selection was regarded as scientifically unshakeable; today, most biologists have their reservations about it. Fifty years ago, Freud's sexual theory of neurosis was accepted by most psychiatrists; today, it is widely recognized that his methods were highly questionable. At the turn of this century, a scientist who questioned Newton's theory of gravity would have been regarded as insane; twenty years later, it had been supplanted by Einstein's theory, although, significantly, few people actually understood it. It seems perfectly conceivable that our descendants of the twenty-second century will wonder how any of us could have been stupid enough to have been taken in by Darwin, Freud or Einstein."

“And the central assertion of his philosophy is that this inner realm is the 'spiritual world' and that once man has learned to enter this realm, he realizes that it is not a mere imaginative reflection of the external world, but a world that possesses its own independent reality.”

“Taken as a whole, the Cross Correspondences and the Willet scripts are among the most convincing evidence that at present exists for life after death. For anyone who is prepared to devote weeks to studying them, they prove beyond all reasonable doubt that Myers, Gurney, and Sidgwick went on communicating after death.”

“Man is as much a slave to his immediate surroundings now as he was when he lived in tree-huts. Give him the highest, the most exciting thoughts about man's place in the universe, the meaning of history; they can all be snuffed out in a moment if he wants his dinner, or feels irritated by a child squalling on a bus. He is bound by pettiness.”

“For Jung, the 'psychic world' was an independent reality, and it was possible to travel there and make the acquaintance of its inhabitants.”

“Normally man’s mind is composed only of a consciousness of his immediate needs, which is to say that this consciousness at any moment can be defined as ‘’his awareness of his own power to satisfy those needs.’’ He thinks in terms of what he intends to do in half an hour’s time, a day’s time, a month’s time an no more. He never asks himself: what are the ‘’limits’’ of my powers? In a sense, he is like a man who has a fortune is the bank, who never asks himself, How much money have I got, but only, Have I enough for a pound of cheese, a new tie, etc.”

“The unbeliever walks for a quadrillion miles, yet one moments of reality makes up for it.”