Parmenides wrote: If you think it, it is.
No one has ever added to the sum total of human knowledge by denying the existence of anything. In order to conceive of something, it must already exist in the collective unconscious outside of time and space. As soon as someone conceive of it, it enters time. If it is then invented, it enters space. Therefore, everything conceivable exists at least as a possibility. However, nothing is certain. There is nothing whose existence can be accepted except as a hypothesis. Everything depends on point of view. Even that we are here. It may be that we are simply being dreamed, As a Bushman once said, “There is a dream dreaming us.”
In the mysteries, initiation was kept secret because no uninitiated person could believe what the initiate had experienced, or even how the initiate was now seeing the world he/she was presently inhabiting. The initiate, however, has learned this new way of seeing; namely, that one must accept all beliefs as hypothesis. As Jung pointed out in The Red Book, to hold beliefs as fact creates wars, magic, and religion, all of which, he said, were the same. Since all beliefs are hypothetical, one can see the world through the lens of each belief as it is presented.