I've been trying to get the higher-ups to consider classifying the fundamental form of human consciousness an SCP, but I don't think they quite get the point. I'm back-saving this into the storage of an empty slot, hoping someone will find and expand further, but I can't imagine anyone following the lead. The people who can't understand it won't, and the people who know will either be too afraid to share it or realize there's better ways to spread truth than shoving a report in someone's face. Reality has to be seen, lived, told, and questioned to be known. Information, data, facts, or knowledge won't cut it if you want your philosophy to truly dream of Heaven and Earth.
I'll describe to you two siblings, and you can probably guess the rest. The first was strong, brave, and trustworthy, while the other was slippery as an eel. Nevertheless they loved each other, and their bond was a true one - the latter would obey any order if their elder gave it, while the elder would commit any dirty trick if it meant protecting the little one. Until they wouldn't. Until the younger committed a crime so heinous, so devoid of human feeling, that the elder realized the day of reconciliation would never come and cut them down, then slit their own throat in despair.
They did not die, but merely changed. As the blood flowed from the elder's neck, as they fell to the ground, they did not remember their life, or regrets, or question why this was happening. The change was already overtaking them. Centimeter by centimeter, in slow motion, they keeled toward the dirt, and as the Earth approached and sight darkened, the Elder saw a tiny plant peeking through the cracked, dry soil. With their last bit of strength, they twisted to the side and landed next to it. Their face lay by the little plant, unblinking eyes stared at its leaves which still trembled from the impact, and the Elder's last thought was "I hope it grows strong around my bones."
The plant grew strong. It wrapped its roots slowly around the ribcage of the elder, it sapped through heart and lung and vein, it drank the blood of the world's second sacrifice, and grew so great that the world around it changed, its thousands of seeds turned the wasteland to a forest, creatures from the sea crawled out to rest and hide in the shade. The tree with a heart of bone saw what it had become and was not satisfied. It remembered its days as a weed, the only thing that could survive in this now-forest. It remembered the thick water it had drank so many eons ago, just as it too was on the verge of death. It remembered being alone.
One day a woman came to the tree who had been exiled from her tribe for an unspeakable crime and was looking to exact vengeance on those who had wronged her. She looked up at the tree, whose top was too far into the sky to see anything other than a shadow, and climbed across its exposed roots, circling it, thinking. She found shelter beneath a root and stayed there for many weeks, speaking to the tree, knowing it was listening even when it did not reply. When she spoke to it, her forehead pressed against its bark, she could feel the hum of life from within. She, like all other creatures of this place, loved the Tree, perhaps more than any of them, for those too scared to approach only knew it from afar. Because they loved the tree, she killed it. Long had she known the words that could do the job, plucked from a dream even before she came here. She stepped to the trunk, pressed herself against it, and whispered.
"There is one who does not love you."
One. Only one. But the Tree knew instantly who this one was, and began to tremble. Leaves, some the size of a man, rained upon the earth, but the woman didn't move. She smiled and prepared another swing.
"They will never love you."
The bark on the tree began to crack. Flakes, some the size of boulder slabs, crashed to the ground. The woman was still.
"They never trusted you, and you will never trust them."
She placed her hand on the broken, quaking bark. All around her was debris, splintered wood, yet she had not been touched.
"Do it, fool," she said.
The tree burst with a crack that shook the entire forest. The shrapnel traveled just barely slower than the sound - little sooner than the crawlers, and climbers, and creepers and keepers heard the noise of destruction and then were crushed, broken, pierced. It was over in minutes, and the world was dead or dying. The woman lay next to the still-massive roots, toward remains of the tree's stump and smiled to herself. A dagger of wood the size of a mouse had pierced her heart, and she lay on the ground, blood passing from her lips. For an instant she lived, staring up at the newly-visible sky, and felt the sun beating down on her. She did not want to die. She knew there could be nothing afterward but dark memories. Yet she was glad she died in the sun, and the sun was glad it could give her last moments light.
She drifted, not in her body, no longer herself, until there was nothing that could be called the woman who killed the tree but a deep, heavy feeling of loneliness. Eventually the loneliness settled on an ant scuttling down a tunnel in a supercolony the size of a city. It was searching for its queen - it had taken the wrong direction, mistaken danger for food, and could not find its way back home. Surrounded by strange skittles, strange signals, the creature clattered madly through hallways that seemed to go every direction, drenched in unfamiliar scents, unending, coiled, ignoring the unfamiliar ants that hissed at this intruder, that clicked their mandibles. It kept going, and going, and going, yet could not find the path to safety.
A warrior watched it go by and was not amused. This intruder had no marks at all of any nearby villages. It must have come from very far away, from a place this Ant-Family had no allegiance with. Recon, perhaps, but incompetent if so. It decided to follow. When the lost ant realized it was being pursued, it scrambled forward as fast as its legs could drag it. It kicked up dirt behind it, collapsed tunnels. Yet the warrior's jaws were strong, and burst through any obstacle until its clamps were leaping towards the head of the intruder. Yet it made an error. It underestimated the lost one's will to survive. The little lost charged forward to meet its pursuer, hooked its own jaws between the vice of its opponent, sacrificed half its fangs to skewer the other through the eye. The warrior collapsed. The lost one fled.
The warrior was given a proper funeral; dissected and fed to the Queen. It sank into her gullet and became new children of the colony, and in this way the colony slowly fought wars of conquest. They were much like the wars up above, where great lines of men in leather and iron marched against each other across the plains, banners bold in the wind, lords leading their men. See that fine light-haired man on the black horse, leading his first battle. He has trained for it many years, learned and squired and fought, and now it is his duty to take the cities of the enemy. How many men will fall today? He thinks. How many by my hand? And his hand tightens around the hilt of his blade.
Yet he is slain by an arrow before even getting a chance to draw his precious father's sword, poor tactics, perhaps, to put your leader so far up to the front like that, but he doesn't think of that as he falls, he wonders instead what will happen to the horse, and the horse to its rider before another arrow skims across its neck and the beast flees, leaves the roaring battle completely, and as it flees it wanders into a sacred place, it sips waters of Light, it becomes graceful and mournful and wise, it gives grace to those who come, and one day it rises even higher, abandons all form, is now only a voice in the wind whispering true tidings, a poem to a beggar, a warning to a thief, and a weeping man in a window hears this whisper, it makes him weep more, for the voice has proven what he always feared, and he looks back at his empty rooms and his silent halls and he leaps, the voice mourns, while many months later a far-off brother tosses an unread-note into a fire and the fire, in hatred of this act, roars to life, clinging to the man as he flees out the door, while he calls for a god or demon to save him, but the gods and demons are locked in their own wars, with no time for mortals, locked in the dance that has always existed and never changes, even as it repeats over and over again, the rhythm each hears and moves to, even as they think their bodies movie, even as they think something different will happen next.
And all of this you know, and feel, and have felt before. Or you haven't. Or now you have for the first time. If you're paying attention, you should be able to continue the story yourself now. Even if you don't, it'll continue without you, but good luck resisting it. Sometimes you'll forget it, sometimes you quite won't be sure how it goes, but it'll always be with you now, always ready to be called upon when you need to understand. May it guide you well, when you need, and not ask for too high of a price.
How to contain it? Well, that's the tricky part. First we need to ask ourselves if it should even be contained. Note that I don't say "could". There is a quite reliable, though arduous and resource intensive, way of properly managing human awareness of SCP-XXXX, though I don't think it would help you much to hear them. They're the type of things that have to be discovered as you go along. It makes the game more interesting.
Hm. And I guess it needs a class, doesn't it? Keter seems grandiose, makes it sound like an emergency. Euclid feels non-committal. Is it a threat or not? We don't use it, it isn't fully uncontainable… Yes, I think know the best thing to do would be just label it Safe.