''The world we live in is a world of effects. Around us, but invisible, are the worlds of causation. They are the realities, while the visible, which lives through the power of the invisible, is the illusion. No matter how deeply we study the material arts and sciences, we can never find out the real cause of anything. Science is still seeking and will continue to search indefinitely for a real foundation upon which to work. The four great questions upon which all knowledge should be based remain unanswered, and science is forced to admit that they are beyond the scope of modern mentality. What is life? What is consciousness? What is force? What is mind? None can answer, for these are invisible things, incapable of being measured or analyzed, consequently no material mind incapable of reason beyond the point of concrete vision will ever solve their riddle. If we would step across the line which divides the true from the false, the spiritual from the material, the eternal from the temporal, we must realize that the Mystery Schools were established in the world so that this transition might be possible. Through the special instruction and understanding gained by membership and graduation from these institutions, man is enabled to become a citizen of two worlds, for the schools themselves are of two worlds. Their gateways are in the material world, otherwise none would know that they exist; but the temples themselves are in the spiritual substances of Nature. In order to reach these temples, candidates must learn to function in the so-called invisible substances. The worlds of causation are invisible only because they are beyond the range of our sense perceptions. By certain forms of culture, however, it is possible to develop sense perceptions at present latent in the average individual. These senses, being more highly evolved than those we ordinarily use, are capable of studying and exploring the so called causal worlds. As power is given to man commensurate to his wisdom and understanding, it is not safe at the present time to reveal to the world at large the methods whereby entrance to the invisible world is possible. If this knowledge were given to selfish people unprepared for their responsibility, they would be able to destroy the universe, either through perversion or ignorance. In order to protect this sacred wisdom obstacles have been placed in the way of its attainment which only the sincere and courageous would be strong enough to overcome. Years of service, self purification and self-mastery must be passed through before any candidate will be admitted to the path of wisdom.'' - What the Ancient Wisdom Expects of its Disciples by Manly Hall

"There have been, and will be again, many destructions of mankind arising out of many causes; the greatest have been brought about by the agencies of fire and water, and other lesser ones by innumerable other causes. There is a story, which even you have preserved, that once upon a time Phaëton, the son of Helios, having yoked the steeds in his father's chariot, because he was not able to drive them in the path of his father, burnt up all that was upon the Earth and was himself destroyed by a thunderbolt. Now this has the form of a myth, but really signifies a declination of the bodies moving in the heavens around Earth and a great conflagration of things upon Earth, which recurs after long intervals… And whatever happened either in your country or in ours, or in any other region of which we are informed, if there were any actions noble or great or in any other way remarkable, they have all been written down by us of old and are preserved in our temples. Whereas just when you and other nations are beginning to be provided with letters and the other requisites of civilized life, after the usual interval, the stream from heaven, like a pestilence, comes pouring down and leaves only those of you who are destitute of letters and education, and so you have to begin all over again like children and know nothing of what happened in ancient times, either among us or among yourselves." - Timaeus by Plato