A. The certain existence of aliens.
– Their ability (The four ways) to move ("universe-canceling" etc.) and communicate ("Telepathic Internet") by methods that bypass distance.
– The lack of interest, common to them and to factors on Earth who know about them, that we will have knowledge of them.
B. The limitation of human consciousness and its inability to see / perceive everything that is in space ("darkness of space") and to store information given through the edge-senses ("constant knowing").
All the rest ("Schools of Galactic Reason", "History of the Bee-Humanoids", "Federation", C's experiences in space, Yahwehs and other extraterrestrial knowledge, ways of using cosmic information) – meanwhile are for advanced and philosophical completion (except, maybe, the last thing).
?And why talk about it
There are many opponents of talking about aliens, and certainly any talk that has information in it. The religious and "conservative" forces, for example, have a clear interest in denying the issue. The religious reaction that is currently threatening from America over the Western world, will not stop at abortions or gay marriage, it will also reach science and its publications, just as it was during the days of the Inquisition. Even today, as C believed and so did other people in our groups, not everything that was revealed is free for publication (and according to what C said, aliens also have an interest, certainly not in our favor, that we will not know anything). There are those who believe that with the development of NASA's research, with the telescopes and discoveries every day of new solar systems, it will eventually not be possible to hide the discoveries related to aliens that have been or will be. We say it is possible, but fear, as C feared, that this celebration may also have an end. And if scientists might have the ability to hide their information in a safe hiding place until the dark passes, for us the only option to leave something in people's memory is to talk about it, write it down. We once thought there was an internet eternity in which all things are preserved. C was skeptical about that too, and indeed many things that have appeared in the past have been erased from internet memory, yet this is the only way we have, to write and hope that something will still be saved from the galactic darkness that may descend, something that will remind people that we are not alone, and that there is more besides us and besides the defective god of the Bibists and Republicans, and the other ass-holes imbued with the motivation of extermination. We as humans in the universe have more options than that, if to old C it once happened.