This thread is an experiment in the line of a previous choice thread I had, but this one differs in that it is focused on some of the philosophical questions raised within fictional universes. And here is the first.
It is the 41st millennium. In the grim darkness of the far future blah blah blah only war, you know the story. Humanity is divided between the servants of an oppressive Imperium and the worshipers of Chaos, as innumerable threats bear down on them. The Necrons are awakening. The Tyranids are coming. The Golden Throne is irreparably damaged and the Astronomicon grows dim. And I think we can agree that this is all Lorgar's fault for being a whiny bastard who would worship anything mysterious that came into his field of view despite being a godlike being himself.
Here is the scenario: We know, indisputably, that humans can survive as part of Chaos. There are breeding populations of humans in the Eye of Terror (and on Slaneeshi worlds, lots of emphasis on that breeding part). Outside threats may still be able to destroy humanity, but Chaos won't destroy humanity. Hell, Chaos is a primarily human faction, all things considered. We also know that the Imperium doesn't have much fight left in it as of M41. It is the strongest operating faction on its own, but everybody else is attempting to destroy the Imperium. Its massive existence means conflicts with the Eldar future-sight are common, the Dark Eldar make a killing (ha, ha so witty) off human pain slaves, the Astronomicon is drawing the Tyranids directly into the Imperium, the Orks consider the humans their best friends, the Tau are mostly irrelevant, and the Mechanicus won't keep their filthy tentacles off Necron Tombs. Shit is bad and the Golden Throne is scheduled to fail, there's no telling what happens then. At the same time, the Imperium is the only thing keeping the defined group of Order factions from all being destroyed, and humanity as we know it can only exist if the Imperium is allowed to continue. The Imperium is also among the only groups to have cultivated a strong anti-Chaos effect, that being the Armour of Contempt that protects against Chaos corruption if their faith in the Emperor gives them enough hate to resist.
Here is the question: Based upon your own ethical reasoning, is it better for humanity to stand firm under the Imperium and continue trying to resist in that way despite the low odds of survival, or is it better for humanity to become one with Chaos and use its power despite the radical alteration that represents?
Points to consider:
-The Imperium is a fascist, theocratic, genocidal hellhole that spurns all progress and rules over trillions if not quadrillions of humans across the Milky Way.
-Chaos changes its adherents via the gifts of the Chaos Gods, and remaining human as we would understand it is no guarantee.
-Most people suffer under the Imperium, but not all, and even so it is able to rule over more people than any other faction.
-Chaos represents both positive and negative emotions, but the grimdarkness of 40K is ensuring it remains firmly in the latter category.
-The Imperium is primarily active, while Chaos is primarily reactive. Chaos as it has been shown does not conceive of future scenarios and plan for them like humans normally do. Even Tzneetch plans only for the sake of planning, and might die if he ever planned for the sake of a true goal.
-Benevolent warpspace entities can exist, as shown by the Eldar Gods, whom were actually worshipped by a great many species. Then Slaneesh ate them because the Eldar decided they wanted to have psychic pleasure olympics instead of a civilization. Note that Isha is still alive as Nurgle's prisoner, Khaine is still alive as a million tiny pieces, Cegorach is still alive in the Webway and Black Library, and that the Craftworld Eldar are planning mass suicide to create Ynnead, a death god they believe will kill Slaneesh and rebirth the Eldar race.
-The warp, and thus Chaos, is formed by the thoughts and souls of mortal beings, most notably humans. As long as there are living beings Chaos will never die.
-The Emperor's true state is unknown. He stopped speaking directly to people not long after ascending the Golden Throne. However, he has also been known to stop time and focus psychic contact upon people even millennia after this. It is possible that the Emperor is dead and the Golden Throne is doing the real work of the Astronomicon.
-The Emperor is thought to be a Perpetual, as Vulkan was. If this applies even to the wounds inflicted upon him by Horus, whom at that point was the living avatar of Chaos Undivided, then logically he will return to health after dying from the Golden Throne failing, though this does not explain why he did not choose to simply die and revive back then.
-Others believe that the Emperor's intense warp presence will lead him to becoming a warpspace entity like the Chaos gods should he die.
-For whatever time period the Emperor is dead or not in control, the Astronomicon will fail and FTL travel will become impossible for the Imperium.
-There is a daemon-infested Webway gate under the Imperial Palace being held mostly shut by the Emperor. Even so, people have reported hearing the Custodes fighting a constant and epic battle behind the doors leading to this chamber.
-There is evidence to suggest that warpstorm incursions such as the Eye of Terror will spill out into the materium unhindered if the Emperor dies.
-Humanity is evolving into a wholly psychic species, exempting untouchables and pariahs. It is not clear if humanity is also developing the secondary powers needed for this process to be viable. Beta, Alpha, and Alpha+ psykers are almost without exception totally insane.
-Papa Nurgle loves you.
-If you're one of those weirdos who considers aliens to be people you can factor them into your answer, as humanity committing to either side will have massive effects on the fate of the galaxy.
-A group of alien seers called the Cabal told Alpharius/Omegon that there were two paths for humanity's future. If the Emperor killed Horus then humanity would persist for another 10,000 years and be destroyed. If Horus killed the Emperor then Chaos would overwhelm the galaxy, but Horus would grow to regret his betrayal of the Emperor and would wipe out humanity in a self-destructive crusade. Chaos would be destroyed by this as it had sunk its teeth too far into humanity and could not survive that loss. Horus is now deader than anybody has ever been dead. It is not 100% certain that the Cabal could be trusted or that Alpharius/Omegon believed them.
-The Immaterium does not obey any laws. Period. And the laws I mean are less those of the Imperium and more those of physics and reality. Anything can happen. After Slaneesh was born in M30 hir existence was established both into the past and into the future, and at the same time one can say zie was never born at all. The Chaos God are simultaneously a memetic psychic pathogen that lives within us all, actual 'physical' entities living in the warp, and mythical beings attributed the actions of natural patterns in the warp, as well as many other things.
I will admit that I have an interest in hearing pro-Chaos arguments since most of canon is strongly pro-Imperium, but I think I've brought up a fair number of points.