"Great actions have shaped our society, the greatest of which, intellectually, has been our casting off of that heavy mantle called religion. Religion damned our species for thousands of years, from the lowest superstition to the highest conclaves of spiritual faith. It drove us to madness, to war, to murder; it hung upon us like a disease. Faith, belief in demons, spirits and an afterlife were simple tools for simple minds to which the vastness of the cosmos was beyond comprehension. It is all ignorance and lies. We have since realised that there are no gods, and no need for gods. We have witnessed the cosmos now, my friends, we have learned and understand the fabric of reality."
- — Herator Prime Kyril Sindermann, on the Imperial Truth
The Imperial Truth is the name given to the atheist, rationalist, and materialist ideology promulgated by the Emperor of Mankind during the Unification Wars and the Great Crusade to reunite all the settled worlds of Humanity in the last two centuries of the 30th Millennium.
It was intended to replace the older traditions of religion, superstition and faith that had long defined many of the worlds of Mankind that had fallen into darkness during the Age of Strife after the fall of Humanity's first interstellar civilisation.
At its heart the Imperial Truth held that the universe was rational, that knowledge defeated fear and brought freedom from the terrors of Old Night. With this assertion went the denial of the irrational, the superstitious, and faith in powers and principles beyond the knowable.
In the unified Terra and Imperium of Man, there could be no mysteries of the soul, no sorcery, no gods. Those who clung to their ignorance were cast down, their lies silenced in the pyre's roar. The terrors of the past had grown in the shadow of superstition and false religious belief. If the Human future was to survive its rebirth, it could not tolerate the delusions of the past.
That there were other dimensions, alien species and mutants who wielded psychic powers was not denied, only that they were supernatural. That some might call these phenomena "sorcery," or attribute them to gods, were simply the symptoms of an incomplete understanding of reality.
With a foundation built upon the tenets of the Imperial Truth, Mankind achieved greatness, and though it was not destined to last, for two Terran centuries the Great Crusade was beyond reproach in its methods and in its glorious elevation of Humanity to become the dominant species of the galaxy.
Of course, there was a degree to which the Imperium and the Emperor touched upon the irrational and ethereal. The new Imperium had grown from the Human past, and secular though it might be, much of its power and nature expressed itself in ways that had echoes of the spiritual. In practices such as the taking of Oaths of Moment, the names of the divisions of Imperial power, and the symbols of that power, the Imperium wrapped itself in the clothes of authority woven from dreams that were as old as the gods it had denied.
And Humanity continued to have faith, faith in the omniscience and benevolence of the Emperor and His designs, faith through reason, in the Imperial Truth. Perhaps this was an intended spiritual crutch; that the Emperor in His wisdom saw the failings in the primitive hindbrain of every man and woman in His service, and recognised that He could only cast down the demagogue and the pontifex in this way. That He could only destroy the spiritual by using the language of religion, by preaching the faith of the empirical and the rational.
It was an inherent contradiction that was never truly reconciled. The onset of the Horus Heresy crushed the growing belief in the Imperial Truth by revealing many of its tenets to be a "Great Lie" -- the supernatural did exist, and religion soon proved to be a crucial component of Humanity's defence against the entities of the Warp.
Ironically, by the middle of the 32nd Millennium, the Imperial Truth had been replaced as the defining ideology of the Imperium by a new and potent Human religion -- the belief that the Emperor of Mankind was Himself a god.
"Unlike you, whelp, I once walked the same ground as your idol. I breathed the same air as him. And I tell you this, without lie or artifice. He never wanted to become what you have made him! He did not wish to be your god-thing. He abhorred such ideals! The slavery of your crippled, blind Imperium would sicken him, if he had eyes to see it."
- — Fabius Bile to an anonymous Imperial worshipper
The Emperor Himself declared that Mankind would never be free to progress and advance to its destined position as the pre-eminent intelligent species in the Milky Way Galaxy until "the last stone from the last church was cast down onto the last priest."
He purged Old Earth of all its ancient religions and superstitious beliefs, even going so far as to personally witness the destruction of the final church on Terra's ancient soil after engaging its resident holy man, Uriah Olathaire, in a battle of ideas, wit and dogma.
The Imperial Truth also held that Humanity was the species which should rightfully rule the galaxy since its physical form was the most pure and all of the other intelligent alien races, such as the Aeldari, had already tried and failed to maintain galaxy-spanning civilisations. An important element of the Imperial Truth's ideology was the belief that it was now Mankind's turn to find a place in the sun and come to dominance in the Milky Way -- and that Humanity was more deserving of such a position than other intelligent species.
The Emperor ordered the Imperial Truth to be brought to all the worlds of Mankind, peacefully at first but imposed by war if necessary, because the Emperor believed that unity was the only way for Humanity to survive and prosper in the face of a very hostile universe. If this required the unfortunate use of force against those who refused to understand this necessity, then so be it.
While the Imperial Truth upheld the light of reason and science, it did have one proscription: Humans must never develop artificially intelligent machines. The Emperor remembered that it was the great war fought by Mankind against the thinking machines known as the Men of Iron that had helped to destroy Humanity's last united interstellar civilisation at the end of the Age of Technology and He had no desire to see the Human race repeat its past mistakes.
As such, when the expeditionary fleets of the Great Crusade encountered advanced Human civilisations in the dark of space that had developed artificial general intelligence, these worlds' populations were simply exterminated outright as potential dangers to the entire body politic of the newborn Imperium.
The Imperial Truth was spread to all of the rediscovered Human colony worlds during the Great Crusade, taught to the troops of the Imperial Army, spread by the Space Marine Legions, and inculcated amongst the populations of newly discovered and Compliant worlds by scores of Imperial Iterators. The Iterators were a corps of orators and rhetoricians of supreme skill and passion who were attached to every expeditionary fleet of the Great Crusade specifically to spread the Imperial Truth.
This creed only further strengthened the Great Crusade, lending the Emperor's symbolic support to all of the scientists, skeptics and thinkers on whom the Emperor's plans for a united, galaxy-spanning Human civilisation hinged. The Emperor needed a new renaissance to begin across the nascent Imperium to see His ambitious dreams for the betterment of Mankind fulfilled.
The Emperor hoped that a new age of science and technological progress would solidify and consolidate the gains He and His warriors had made in achieving a new place for Mankind in the galaxy, a restoration of Humanity's rightful place as the predominant intelligent species in the known universe.
However, the dominance of the Imperial Truth was already under attack solar decades before the Horus Heresy even began. A text known as the Lectitio Divinitatus calling upon all of Humanity to recognise the Emperor's divinity as the one, true God of Mankind had been authored by none other than the Primarch Lorgar of the Word Bearers Legion.
Lorgar had been raised on Colchis, a theocratic Feudal World dominated by priests and the worship of the ancient polytheistic gods of what was called the "Old Faith." Lorgar had overturned the Old Faith in pursuit of a new religion called the Covenant of Colchis that saw the Emperor as a god incarnate after Lorgar had suffered from visions throughout his youth of a god-like figure that would eventually stand beside him.
These visions, probably psychic in origin, proved true when the Emperor came to Colchis to collect His lost son. In the interim, Lorgar, alongside his mentor and foster father, the Covenant's high priest Kor Phaeron, had launched a successful six-year-long holy war against the adherents of the Old Faith on Colchis to force them to convert to the worship of the Emperor.
After Lorgar finally met his father, he penned the Lectitio Divinitatus which taught that the Emperor was the only god deserving of worship by Mankind. The text spread rapidly through the expeditionary fleets of the Great Crusade, and received more support amongst the civilians and support personnel of the fleets and Compliant Imperial worlds than with the Imperial Army's officers and the Legiones Astartes, who believed more strongly in the Imperial Truth because of their closeness to the Emperor.
Yet, over time many of the people of the Imperium became convinced that the Emperor was truly a divine being and Emperor-worship cults began to spread, gaining more momentum as the onset of the Horus Heresy approached and the influence of the Dark Gods began to wax across the galaxy. This process was accelerated since the Word Bearers would convert every world they made Compliant for the Imperium to their new faith.
This policy made that Legion's progress much slower than that of the other Legiones Astartes and ultimately led to their brutal humiliation as failures in the Great Crusade before the Emperor Himself on the world of Khur, one of the planets where they had successfully spread the faith of the God-Emperor.
This savage rebuke came only after the Emperor ordered the Ultramarines Legion to destroy the great Khurian city of Monarchia where He had been openly worshipped as the God of Mankind. This humiliation played a major part in Lorgar's corruption and fall to Chaos, allowing his First Captain Kor Phaeron and First Chaplain Erebus to convert him to the worship of the Chaos Gods -- the true deities of the Colchisian Old Faith -- and corrupt his Legion.
Lorgar had always rejected the Imperial Truth and believed whole-heartedly that religious faith was what truly made Mankind strong in the face of adversity. If the Emperor rejected his worship, than he was determined to find the gods of the Colchisian Old Faith that he had once warred against and offer them his devotion. He led a portion of his XVII Legion|XVIIth Legion]], the Chapter of the Serrated Sun, on what became known as the Pilgrimage of Lorgar to find these true divine beings.
Lorgar ultimately made contact with them near the world of Cadia close to the Eye of Terror after a journey within that massive Warp rift that marked the death of the ancient Aeldari Empire. Lorgar willingly gave his soul to Chaos Undivided once he learned that there were truly gods in the universe and that they welcomed the worship of Humanity. Lorgar became a secret, devoted servant of the Ruinous Powers who feared the imposition of order over the galaxy that the Imperium brought.
Lorgar spent the next several solar decades slowly positioning the pieces of a great plot to convert the Space Marine Legions to the service of Chaos and ultimately initiate a great revolt against the Emperor in the name of the Dark Gods.
The Imperial Truth slowly died away as the Horus Heresy progressed and religious faith in the Emperor seemed to offer both spiritual succor and real psychic protection against the growing strength and daemonic threats of the Ruinous Powers.
Just as the Word Bearers had once converted whole worlds to the worship of the Emperor, now Lorgar imposed the bloody worship of the Dark Gods upon every world they captured during the Heresy, forcing the inhabitants to memorise his new work of faith, the Chaos-tainted Book of Lorgar.
Once the Horus Heresy ended in the defeat of the forces of Chaos and the Traitor Legions fled into the Eye of Terror during the Great Scouring, the Imperial Truth's hold on the hearts of Humanity retreated even more rapidly.
Without the Emperor's guiding influence and constant reaffirmation of His desire for the establishment of an Imperial culture based on secular rationalism and materialism, superstition and religion crept back into the hearts of Mankind.
Lorgar had been right about one thing: religion did provide a far surer way to bind Humanity together than reason and science. Belief in the Imperial Truth slowly eroded, year by year, world by world, until the Adeptus Ministorum was officially established in the 32nd Millennium and the Imperial Cult was recognised as the state religion of the Imperium by the High Lords of Terra.
The Imperial Cult combined the widespread Human beliefs in the God-Emperor who protected Humanity from the terrible dangers of the universe into a single, unifying religion that would sweep away the Imperial Truth as false and heretical dogma.
Ultimately, the Imperium's state religion led Mankind towards a decline into ignorance, superstition, intolerance and tyranny, the very things the Emperor had fought so earnestly against. Ironically, by the 41st Millennium, the Imperial Truth itself would be seen as a heresy punishable by death at the hands of the Ecclesiarchy or the Inquisition.
During the dark days of the Horus Heresy the power of the Warp reached ascendance, the ruinous entities within drawn closer to the narrow divide between the Empyrean and realspace than had been experienced at any time since the Age of Strife.
Knowledge of the existence and madness of that which lay beyond the veil reached its height among the worlds of the Imperium. Whether through first-hand experience, reliable eyewitness accounts, dark rumour or the frantic babbled hearsay carried by uncounted refugees in flight, the citizens of the Imperium at a stroke learned that the Daemons which they had so long denied were in fact real.
With this realisation, panic and dread spread to become a galactic hysteria. The threat of the approach of the forces of the Warmaster Horus only fanned the flames of agitation; on many worlds the fever pitch of terror ground to a halt any hope of resistance as the Traitor Legions arrived, the gatekeepers of these worlds paralysed with terror or already fleeing.
The Warmaster understood the power of fear and used it widely as part of his strategy of conquest. Sending his emissaries ahead of his fleets, Horus spread word of the Emperor's Great Lie and threatened to unleash the arcane powers he now commanded to cow populations into submission.
Worlds lost to the Warmaster were said to have become "dark." This sentiment was both figurative and literal. These worlds would immediately cease all trade and communication with their neighbours, their spaceports would be blockaded and their astropathic choirs silenced. The flood of refugees escaping the onrush of the Warmaster's armies would dry up, with only a rare few voidships allowed to escape, carrying fear as a weapon to break other worlds.
Among the refugees were the Warmaster's agents, insinuating themselves into positions to destabilise neighbouring star systems. To many observers, it appeared as if the darkness of space drew close to these lost worlds; isolated they would regress to a state pre-dating Imperial enlightenment. Fortress Worlds of the Imperium slipped into darkness and simply disappeared, never to be seen again.
Many worlds were stripped barren by the Warmaster's engineers of war, their people and resources pressed into service in the Warmaster's fleets and armies. Industrial and Forge Worlds were captured and their denizens enslaved to continue production in actions known as "Dark Compliances." Other worlds found less useful or more resistant were scoured of life by dread atomic fire or the Life-eater virus. Still others were sacrificed wholesale to maintain the power of the Ruinstorm, the great Warp Storm created by the Traitors to divide the galaxy and prevent the Loyalist Space Marine Legions from reinforcing Terra. Such a sacrifice was perhaps the worst fate of all for those worlds conquered by Horus.
As worlds cascaded into darkness, conditions became ideal for all of the evils of space to emerge. Freighters full of refugees would carry within them a melting pot of worshippers of ancient religions, and for surely the first time, many different such cults would mix, each carrying a piece of a larger and more complex black ritual.
The sequence of worlds becoming dark would lead to tidal waves of fearful emotions carried by billions of people, which would in turn be reflected in the psychically reactive dimension of the Warp, leading to indiscriminate, large-scale daemonic incursions on dozens of worlds. Rebels and cultists across the galaxy threw off the pretence of Imperial Compliance to challenge their Imperial planetary governors, and such distractions to loyal defenders only paved Horus' advance.
Other forces took advantage of the Imperium's weakness. The Unspeakable King would re-emerge, as would the psychopathy of Du'Maash. Xenos threats banished to the fringes of the galaxy would rear their heads to eke out a corner of the Imperium as their own, and those within cordons of quarantine would look to their skies to see the battleships of their Imperial gaolers no longer hanging above them.
In many instances, the fearful tales of the Daemon abroad within the Imperium ravaging loyal systems may even have been misattributed to the influx of rampaging xenos breeds taking advantage of the Imperium's tumult, but given the paucity of surviving records, it is impossible to say what fates befell such worlds.
Many questioned at this time if more could have been done to stem the rising panic. The Legiones Astartes, the symbol of Imperial strength and unity, were sundered after the bitter blows at Isstvan III and Isstvan V, Calth, Signus Prime and many more. The Shattered Legions' forces scattered across the vastness of the galaxy waged their guerrilla campaigns to harry the onrush of the Traitors' darkness, but could do little to significantly slow it.
The vast martial might of the Imperial Army was split in twain by the rebellion, responding to a million cries for aid or consuming itself with in-fighting. Planetary garrison forces could scarcely keep up with the deluge of refugees and quickly became wary of their neighbours, mistrust winning over compassion thanks to the artifices of the Warmaster.
With Imperial defenders in disarray, voices were raised to ask questions of the whereabouts of the Emperor and His agents of illumination, those most trusted and most required to keep the darkness at bay in the Imperium's time of need.
The Emperor had returned to His seat on Terra after the Triumph of Ullanor, trusting to His chosen son, Horus, to complete the Great Crusade, while unbeknownst to His Imperium He was embroiled in His Imperial Webway Project. It may have appeared to the masses that, throughout the years of the Horus Heresy, He was either unaware or uncaring of the plight of the trillions of souls looking to Him for deliverance, and with the weight of that perception came despair.
The truth though is far more frightening, as the secrets being unlocked in the Imperial Dungeons beneath the Imperial Palace were of the utmost importance, holding the full attention of the indomitable mind of the Master of Mankind, allowing Him no respite in which He could turn His gaze to the stars. With Him, His Custodians retreated to Terra, playing little significant part in the wars of the Horus Heresy, instead seeing to the safety of the Emperor and enacting His secret will during the War Within the Webway.
So too did the Imperial Fists Legion and their Primarch Rogal Dorn return to Terra, tasked with the fortification of the Throneworld. Beyond the light of Sol, the Imperial Fists were instrumental in the defence of the heartlands of the Imperium within the Segmentum Solar, here at least they monitored the flow of rumour and brought reassurance to isolated planetary governors that they were not forgotten.
These efforts were often undermined in the early stages of what would become known as the Solar War, a campaign of calculated misdirection and manipulation whose objective was to weaken the seat of power of Terra prior to the Warmaster's arrival.
The Forge Worlds of the ancient Mechanicum, ever jealous of their domains, became isolationist and reclusive, beyond the reach of Mars and Terra both. The fate of the fanatical Malagra Order which served as the internal doctrinal police of the Machine Cult is tied to the birth of the Dark Mechanicum, and as with many masters of the Forge Worlds, they had little interest in the plight of the wider Imperium, being as they were otherwise occupied with the division of the Mechanicum and the secession of Mars from the Imperium.
Of the Chartist Captains and Rogue Traders in the galaxy, they made themselves known in many small ways, arriving unheralded to aid the Imperium or, in their disbelief and shock, let loose their anger at the very idea of civil war; punishing both the Emperor's and Warmaster's forces in equal measure. Such was observed when the Golden Fleet appeared to burn the skies above Tallarn, and when the Admiralty of Joss crippled the moon of Drussen IV.
Multiple Rogue Traders are thought also to have contributed on both sides to the Sea of Fire, the devastating void warfare engagement across the Beta-Garmon region fought during the Battle of Beta-Garmon. On the whole, their forces were too far from the core worlds in need of their aid, too scattered to make any concerted impact on the wider war and too few to turn the tide.
As to the Order Elucidatum, the secret police of Malcador the Sigillite, Horus knew of their presence within the Great Crusade. Being a skilled general, he had observed early on certain regiments of the Imperial Army peeling off from their ordered advances to pursue hitherto unknown objectives and had traced these back to the offices of the Sigillite. When he came after the Isstvan III Atrocity to purge his voidships of Iterators, Remembrancers and Imperial bureaucrats he did not underestimate the Elucidators, tasking his Equerry Maloghurst with their extermination.
Outside of the Traitors' fleets, the Elucidators found their work outstripping them as the birth of the Ruinstorm gave rise to innumerable new targets, far beyond the ability of their order to cope with alone, particularly when those among the Imperial Army whom they had come to rely on were entrenched in warfare on multiple fronts.
The individual Elucidators became fragmented as the Heresy proceeded, their fates unknown and unsought after. From the text concerning the Alpha Legion's actions during the Heresy known as the Unbalanced Scales, we can deduce that perhaps dozens of Elucidators spread throughout the expeditionary fleets were in fact covert double agents of the Alpha Legion and, at the onset of the Horus Heresy, these were recalled to other, unknowable posts.
In 012.M31, the Order Elucidatum was formally dissolved by the Sigillite without fanfare, and records pointing towards its existence expunged. Those few Tallymen who survived to return to their master on Terra were not lauded as either heroes or villains but quietly inducted into different secretive Imperial agencies, for Malcador was still in need of proven men and women with their particular skills.
The Great Lie
"Once you burned our churches, our places of power and called us fools. Now the wheel has turned. You have unleashed that which we sought to appease and you bring me up from the darkness of your prison in search of weapons. I will not aid you, for I know the foe you face and the hell they will bring to you brings me only joy."
- —Attributed to Kamren Athern, convicted theocrat shortly before his execution in 009.M31
From the seemingly endless cycle of tragedy and death Horus unleashed, it has become clear to all that at the heart of the Imperial Truth was a lie. This "Great Lie," promulgated by the Emperor who now sits eternal upon His throne, is that of a calculated and hidden ignorance within the doctrine of enlightenment.
Those possessed of psychic gifts who had truly seen behind the stars knew that the Lie resided there all along, clearest in the darkness, though they feared to think of it and dared not speak of it: the Warp is alive with malignant sentience, the very essence of which IS supernatural.
These unquiet spirits, which reside in the Warp, sate themselves upon the souls of mortals. Those that remain must examine the consequences of the silence on this topic and the toll what some would call the "Great Lie" took upon the Imperium with the outbreak of the Horus Heresy.
The first of these consequences may appear now to be the most terrible; that of Horus' rebellion itself. By turning his face from the light of his father, Horus not only brought ruin to the Imperium but also empowered the beings of the Warp to cross from their empyreal realm into realspace. It is claimed that Horus was closest to his father among the primarchs, and that the Emperor shared with him all of His accumulated wisdom.
This can only be a falsehood, for Horus must have learned of the power of the immaterial from some other source -- the Emperor would otherwise surely have warned off His son from the dangers of the forces he later came to enter into a compact with.
The White Scars Legion primarch, Jaghatai Khan, mused upon returning to Terra that, "It was the knowledge that the Emperor had concealed His true purpose from His favoured son that led to Horus' downfall. In Horus' mind, the suspicion took root that he may not have been his father's favourite; after all, my brother Magnus knew more of the Warp and Corax more of the darkness within Mankind. This must be what broke Horus' will."
Captain Garviel Loken, a survivor of Isstvan III, is heard to have countered bitterly, "It was simply the realisation that the Emperor was not infallible, as all sons learn of their fathers, which set Horus' heart to fester."
It is impossible to say now, for Horus too is dead and his ashes reveal nought.
There have been other costs incurred by the Great Lie which have undermined the Emperor's dream of Imperium. Many billions of lives were lost in the purges later required to maintain it. Ancient civilisations, directly descended from Old Earth, who carried with them across the cosmos the torch of religions deemed anathema in this enlightened age were simply murdered for their beliefs.
Tens of thousands of cities were burned, cultures were put to the sword and worlds were annihilated in the name of the Imperial Truth. Ignorance was promoted hand-in-hand with enlightenment across the stars. The stability and safety of ignorance was used as a tool, an opiate to the blissful masses, through which they would remain unquestioning.
With ignorance and death as the tools used to promote wisdom, the Great Crusade ultimately made vulnerable the very foundations of the Imperium. When push came to shove, it made possible the later use of the ignorance of blind faith as a political weapon against Humanity itself.
There is a final and more dire consequence, one which revealed itself in the due course of time. A greater war had begun with the end of the Horus Heresy, which blighted the future of Mankind. Once son had turned upon father, brother upon brother, and the Imperium's greatest defenders had been brought to their knees, Humanity could never attain the greatness of galactic dominance that the Emperor had intended for Mankind.
Therein lay the problem, for in his reckless ambition, Horus mortally wounded the Imperium. The threat of the alien which the Imperium spent two Terran centuries casting from its growing borders during the Great Crusade had received a great reprieve. Moreover, the very fabric of reality had been altered and terrors previously unknown to Humanity had turned their eyes upon the domain of Mankind.
The xenos and the Daemon could not allow the Imperium to recover the might of its golden age; from the Heresy forwards, they have always sought to bring Mankind low, for Humanity's weakness kept them strong. They would forever after circle the wounded Imperium looking for every crack in its defences to bring it one step closer to destruction.
Necessity of the Lie
Though the learned now question the complex and delicate balance of philosophies the Imperial Truth put into motion, for all that came to pass the Emperor was no fool. He was without doubt aware of the hypocrisies fundamental to the tenets of the Imperial Truth.
That the entities within the Immaterium pose a danger to the Imperium is without question, but to suppress their nature rather than to educate His subjects, to deny enlightenment in what He hoped to become the Age of Enlightenment, cannot have been a path lightly trod. It can only be concluded that the Emperor was aware of the risks and enacted a calculated strategy to protect His greater purpose.
The need for the Great Lie is a matter of some speculation. Some have argued that the Emperor's goal was to defeat death itself by excising the soul and that knowledge of the existence of a soul within the Warp would be Humanity's downfall. Others thought that He sought to enter the mind of every Human being in the galaxy and alternatively impart His phenomenal knowledge or His psychic gifts, creating an ultimate, ascended race of Mankind.
Yet others have quietly suspected that He wished nothing less than dominion over all of reality and unreality, and hid the supernatural nature of unreality such that no being would dare challenge His claim upon it. Darker rumours, those which were whispered during the days of the Emperor's seclusion on Terra to construct the Webway Project, surmise that He sought to reach the apotheosis of godhood for Himself, leaving Mankind behind with the cold revelation that the Imperial Truth was a lie and the gods real.
Whatever the case, it was clear to the Imperium from His retreat to Terra at the pinnacle of the Great Crusade after the Ullanor Crusade, as well as the endless parade of people and machines descending into the Imperial Dungeon beneath the Imperial Palace, that some vast and intensive artifice was underway, which served only to fuel further speculation.
It may even have been that the entirety of the Great Crusade served only to acquire the mysteries and materiel required to meet another objective, and that the Imperial Truth was simply a means to an end -- never intended to withstand a test such as that which Horus' Traitors brought against it.
Knowledge could have been Mankind's greatest weapon. The sword of knowledge racing across the stars with the Great Crusade could have empowered Humanity to know the Daemon and to combat its insidious presence. The shield of ignorance with which the Emperor hoped to protect Mankind could only ever stymie the flood of darkness, never halt its onslaught.
It frayed and buckled as any shield is wont to with the hammering of the enemy upon it. The Emperor's gamble with the fate of Humanity was ultimately a failure, and His denial of the true nature of the Warp a mistake. The Emperor could have stopped all of this, Horus' rebellion, the ascendance of the Warp and the near-ruination of the Imperium, if only He had told His sons and His subjects the truth.
Though the Emperor's plan may have failed, surely no one, alive or dead, could have known more of the consequences of His decisions. Had others known what the Emperor did, it is an open question whether they might have produced a better outcome.
Regardless, none can be sure of the ultimate solution He foresaw, only that the threat must still be countered if the Imperium and the species it serves is to survive.
Upholding the Imperial Truth
While the very nature of the Warp is unreal, the threat posed by the Daemon extends beyond the metaphysical to tear at the very foundations of reality. Many would choose to deny that this threat was real, and for them the armour of ignorance would be shattered alongside their fragile sanities during the Horus Heresy.
For those who sought to hold the darkness at bay -- the organisations established through the years of the Great Crusade -- the threat which they girded themselves against was a very practical concern. These dauntless protectors would struggle to endure in the tumult of unreality unleashed by Horus and his allies, though they would clad themselves in the armour of knowledge, and wield powerful weapons in the forms of archeotech and psyarkana -- the arts of psychic technology.
These weapons of esoteric provenance were both as real and as unreal as the sinister denizens of the Warp, and were used to turn the arcane against the Empyreal. However, such potent weapons hold edges which cut both ways, and the Imperium would suffer under the attentions of its own protectors.
During the terrible period of history known as Old Night on Terra, the Age of Strife, evil rose to its zenith in the galaxy. For thousands of Terran years, unabated horrors assailed the isolated worlds of Humanity, bringing it to the very brink of annihilation and reducing Mankind to a pitiable species, a shadow of the glories of its past.
This era of horrors, perpetuated by vivisector-warlords and techno-barbarian tyrants, was marked by plagues of insanity, the scourge of famine and the tragedy of unending war. Worst of all of the terrors faced by Humanity in this era was the incursion of the Warp, brought about by the emergence of ever more psykers and the machinations of sorcerer-kings.
Human worlds were swallowed whole by the Warp or else subjugated to become the slaves of Daemons. On such worlds, the Human body became inconstant, rife mutation twisting the shape of men and women beyond recognition into something entirely alien.
Cruelty, brutality and suffering were the only constants of this age -- this is the galactic anarchy which the Emperor opposed and the horror of the darkness which the Imperial Truth was employed to hold at bay.
If upholding the Imperial Truth was a necessary evil of the galactic dominion the Emperor sought to achieve, it also served many purposes in the growth of the Imperium of Man, from the breaking up of communities which shared common beliefs that might oppose Him, to creating an equality of opportunity such that any citizen of merit might rise to prominence of their own accord.
Furthermore, by breaking the tribalism and in-fighting different cultural groups had held for Terran millennia through the creation of a single Imperial cultural doctrine, and by freeing the Imperial populace of the cosmic dread which mortals feel when contemplating the vastness of the galaxy, the Emperor enabled all of Mankind to set their focus towards the single goal of the Imperial dream.
These are all noble and rational causes, though they are shadowed in significance by what appears to have been the greater advantage, as observed by those who were aware of the Great Lie. Every religion, ancient and esoteric, encountered by the Great Crusade in two standard centuries shared one common factor: that worship draws the attention of the Ruinous Powers within the Warp.
It would not be beyond reason to posit that one of the secret motivations of the Emperor in promulgating the Imperial Truth was to weaken the psychic threads which bind Humanity to those foul sentiences in the Empyrean, and break the grasp of the Ruinous Powers. Given the vital importance given to the notion that the Imperial Truth became a universal galactic doctrine, the means taken by the Emperor and Malcador the Sigillite to ensure that it was enforced were many, and in some cases, extreme.
However, their consistent purpose points to some justified ends being served which may be unfathomable to lesser, merely Human intellects. This purpose was to suppress at all cost wider knowledge of the supernatural nature of the Warp. To this end, specific and covert Imperial bodies were created, and for the duration of the Great Crusade they largely succeeded.
Foremost and most well-known of these bodies acting in support of the Imperial Truth were the tools of the vast Imperial propaganda machine. The Iterators, that order of rhetoricians, philosophers and educators, were primed with the express purpose of propagating the message of the Imperial Truth throughout the Great Crusade.
They would ply their trade on every Compliant world newly entering the Imperium, as well as reinforce the secularity and rationality of the tenets of the Imperial Truth on worlds already part of the Imperium for solar decades or standard centuries.
The Iterators were recruited from the most erudite, sharp-witted and silver-tongued teachers of Terra, men and women trained at the direction of Malcador the Sigillite to have such a firm belief in the Imperial Truth and keen grasp of rhetoric, debate and diplomacy that when making their orations they could smother any arguments, however sensible, to the contrary of their specific dogma.
While considered an overwhelming success from the perspective of the great and good of the Great Crusade, on many worlds the speech of Iterators was seen as bombast and unconvincing, for deep-seated strictures and beliefs cannot be easily changed with the introduction of new and often inflammatory concepts like atheism.
The master of Jungmagr is recorded to have said of the army of Iterators which spread among his populace after that bloody Imperial Compliance action, "Better fangs chew'd us through, than left these serpents' honeyed tongues to turn us, for snake is root of our evils and woes befall us now forth."
Though many Imperial Compliance actions may have seemed peaceful thanks to the work of the Iterators, more often than not it was the threat of the bolters of the Legiones Astartes standing at the Iterators' sides which cowed worlds into Compliance, rather than eloquence and logic.
As the pre-Imperial adage goes, "a mind changed against its will is of the same opinion still" and as such should have been more closely heeded, for in the haste to move on to greater conquests, the Great Crusade left behind a string of worlds ready to reject the Iterators' platitudes, ripe for the influence of the demagogue and the powers of the Warp to fester and ferment rebellion.
Talons of the Emperor
After the Iterators, the primary armed enforcers of the Imperial Truth were thought to be the Talons of the Emperor, and at the Sigillite's behest, the callous, grey-clad secret police force known as the Elucidators.
Being at the Emperor's side throughout the Unification Wars and the Great Crusade, it was only natural that His Legio Custodes were His weapon of choice when He intervened personally in esoteric matters, no command given by the Master of Mankind being beyond the ability of the Custodians to carry out.
Beyond reproach, the Legio Custodes were given a lighter hand than any other Imperial force when it came to the handling of the forbidden and dangerous artefacts of the occult. It was their duty to apprehend and interrogate persons with knowledge of arcane sciences and access to forbidden archeotech, learning all they could and capturing any relics of significance worthy of future study or use to the Emperor and His technicians.
While most such individuals were summarily executed after their secrets were extracted, some few were of value and thusly offered a choice to serve the Master of Mankind rather than be put to death.
The Sisters of Silence were known to be witchseekers, and though they served their quiet purpose to hunt out valuable Human psykers for the choirs of the Astra Telepathica, it was also at their discretion to further investigate the activities of a rogue psyker. Such investigations were wont to reveal the usage of a developing psyker with ill intent by a cult or through the abuse by local elites of ancient and forbidden practices.
Whether such occurrences were accidental or intentional, to have touched the other side taints a psyker and any persons with which they were in contact, resulting in the wrath of the Sisters of Silence being unleashed upon a locality in the form of Pursuer cadres, Erinyes Jetbike squadrons and the dreaded Divider stealth-craft.
When death was the only solution available, the Officio Assassinorum could also be employed, but in those rare instances of extremis where such death was required as to end an entire world for the perfidy of making foul compacts with the entities of the Warp, the Psi-Titans of the Ordo Sinister could be unshackled, bringing ruination wherever they trod.
Space Marine Legions
The Imperial Fists Legion is thought to have also been subtly employed by the Emperor to combat daemonology. The nature of the Imperial Fists is one of stoic adherence to duty, a zealous loyalty engineered into the core of their genetic code, steeling them against corruption. Though they are known to be His consummate defenders, their purpose may have been to defend more than His walls, but also the soul of the Imperium.
For much of the Great Crusade, the Emperor kept the VIIth Legion and their primarch, Rogal Dorn, close to His side. Unlike his brother Magnus the Red, Dorn could not be easily swayed to seek knowledge for its own sake, instead he was trusted to exercise restraint and caution in his studies.
For this reason, it is rumoured that the Emperor, over a period of solar decades, shared secrets with Rogal Dorn which but a few individuals were privy to; allowing the Praetorian of Terra to better understand the need for the Imperial Truth and the urgency with which the true enemy must be combatted.
During the Great Crusade, the Imperial Fists came to uphold the Imperial Truth with a passionate zeal. As they encountered sorcerers and preachers of the profane, they understood and were able to identify their enemy's weaknesses, pioneering the use of an arsenal of psyarkana devices capable of combating the influence of the Warp.
Throughout the course of the Great Crusade, Rogal Dorn accumulated one of the Imperium's greatest repositories of the arcane within the vast vaults of Phalanx, a valuable resource kept hidden from his primarch brothers which, though he was reticent to employ it, was of great use during the Siege of Terra.
The Death Guard Legion too played a role in enforcing the Imperial Truth. Mortarion, in his hatred of the daemonic and its sorcery earned during his life on Barbarus, actively sought out worlds tainted by what he perceived to be the foul influence of the Warp. On these worlds he acted not as the Liberator of Barbarus, but as a Reaper, the Death Lord come at the head of a host of the XIVth Legion's Destroyers to harvest the souls of those he saw as diseased.
Mortarion's warriors were among the first to make widespread use of the Bale Flamer and so-called psyk-out or psi-reactive munitions. The taint of Warp magick was to Mortarion the most terminal and incurable of contagions, and was a sickening blight, relentlessly in need of eradication.
Other Imperial organisations also directly or inadvertently upheld the Imperial Truth. The technophages of the Malagra, the ancient Mechanicum's internal function of cleansing, for a time acted to maliciously hinder the works of any magi tinkering with the dangerously cryptic.
Within the Mechanicum, the adherents of the Malagra doctrines sought to maintain the purity of the inner workings of the cults of the Omnissiah. They were the hunters of Heretek magi, and were known to declare dormant whole forges if any spoor of the highest forbidden heretechnical orders of damnation were found within, such as the curse of artificial general sentience, the melding of xenos technology with the blessed machine, or the drawing of energy from the Warp directly.
Among the Chartist Captains and Rogue Traders too, certain precautions were taken against the threat of the Warp. Operating at the distant borders of the galaxy and frequently traversing the Immaterium, these starship captains encountered arcane phenomenon beyond description; sights and sensations which drove men and women mad with but a fleeting glance.
Often, they would operate independently, away from Imperial scrutiny, where they could take their own measures to ensure the safety and security of their vessels.
When threatened by the xenos or the Daemon, such captains, many scarcely more than buccaneers, would have had the means prepared with which to respond with force and resourcefulness in kind, though they might never dare to declare such within the bounds of the Imperium.
- Horus Rising (Novel) by Dan Abnett
- Galaxy in Flames (Novel) by Ben Counter
- The First Heretic (Novel) by Aaron Dembski-Bowden
- The Horus Heresy Book Two - Massacre (Forge World Series) by Alan Blight, pg. 139
- The Horus Heresy Book Eight - Malevolence (Forge World Series) by Neil Wylie and Anuj Malhotra, pp. 9-11, 24-25, 27-31, 231