Inquisition - Radicals: Radicals have deviated from the tenets of the Imperial Creed. They vary immensely in their beliefs, from those who use the forces of the Warp against its inhabitants to Inquisitors who seek to shatter the very Imperium they serve. A Radical will often say that all Inquisitors start out as Puritans, but that as they are exposed to the realities of the Imperium and the galaxy beyond, they inevitably become more and more flexible in their ideas and all become Radicals in the end.Puritans, on the other hand, consider the more extreme Radicals to have been corrupted by the very power they wield and the dreadful knowledge to which they are exposed.Most Radicals try to conceal their divergent beliefs when in the company of many other Inquisitors, preferring to pursue their agendas away from the sight of more puritanical souls. Some, however, are outspoken in their views and can gain many enemies in attempting to convert Puritans to their cause. Inquisitors are generally wary of such beliefs within their Acolytes, at least until they have proven themselves over many successful investigations.Xanthism - The most powerful and obviously Radical grouping within the Inquisition, Xanthites advocate the use of Warp-based weaponry, such as Daemon-possessed swords, Daemonhosts, and other tactics that will turn the power of Chaos against itself. Xanthism is one of the oldest philosophies of the Inquisition, named after Inquisitor-Master Zaranchek Xanthus, who was executed in the 32nd Millennium as a Heretic for reputedly possessing a dangerous and unhealthy amount of knowledge of the Warp and its uses. Note that, unlike other Inquisitors, only the rare openly Xanthite Inquisitors will be denied the use of the Grey Knights if they requisition them. Xanthites are considered too impure themselves to be given command of the Grey Knights; more Puritan Inquisitors fear that they may actually be leading those elite Space Marines into a trap in service to the powers of the Warp, whether they realise it or not.Horusians - A sub-sect of the Xanthites, this sect wishes to create a new leader for Humanity, much like the Puritan Thorians. Both factions strive for a powerful, god-like figurehead to lead the Imperium into a new golden age. But the Horusians view the might of Horus as a wasted opportunity; they believe that should the limitless power of Chaos be harnessed and bound into a great leader of men, Humanity could once more become united and crush all before it. Needless to say, even other open-minded Radical members of the Inquisition view the Horusians as dangerous in the extreme, likely to become nothing more than traitorous pawns of the Ruinous Powers.Recongregationism - The Recongregators believe that the Imperium, after long millennia of stagnation, has become decadent and corrupt. To remedy this, Recongregators believe that only through change can the Imperium hope to prosper, believing that the greatest threat that Humanity faces is its lack of progress and terminal stagnation. Working quietly behind the scenes, the Recongregators seek to influence or engineer events that will lead to change and progress. It is a subtle game, and of all the major factions of the Inquisition, they are counted amongst the least visible, keeping to the shadows whilst others charge into the fray. They are most deeply opposed within the Inquisition by the Puritan Amalathians.Istvaanism - Even more extreme in their views than the Recongregators is the Radical faction known as the Istvaanians. Taking their name from the infamous massacre on Istvaan III, where Horus virus-bombed the remaining Loyalist Space Marines in his Traitor Legions, said to have been the spark that ignited the Horus Heresy, they seek to ferment conflict and crisis wherever they tread. It is their belief that the Imperium requires constant strife to survive (a reasonable assumption given the galaxy's state of near total war), and if Mankind were ever to find itself at total peace, the Imperium would collapse and decay. To this end, Istvaanian Inquisitors seek conflict head-on, instigating discord within and without the Imperium, starting wars, leading invasions, and stirring discontent into rebellion.Antiquarti - The Antiquarti are a Radical faction within the Inquisition. Originating from a group that split from the Ocularians led by Inquisitor Thaddeus Hakk, they focus on discovering patterns and events in the past to predict the future.Casophilians - The  Casophilians are a Radical sub-faction of the Thorians who dedicate their studies to the process by which the Human soul transitions from realspace to the Warp. The Casophilians know that daemonic entities can pass through the barriers between the Warp and the mortal world.  This makes them profound experts in the arts of daemonology with a special regard for ritual summoning rather than incidental or malicious possession. They hope to find the means to bring back a deceased man or woman's soul to the mortal world. If these actions are successful, then it would be the first step in bringing the soul of the Emperor back into realspace in a suitable mortal form. Further aspects that differentiate the Casophilians from other Thorian beliefs is the fact that they openly embrace new ideas on their theories and thus work closely with Inquisitors of other factions which prevents them from adopting a general, isolated view of their studies' importance. This allows them to learn much from their interactions with other branches of the Inquisition and allows them to gain greatly from their experiences. Amongst the different philosophies held by the factions of the Inquisition, the Casophilians are often known to work in conjunction with members of the Puritan Anomolian Beholders as both factions study the soul; the Anomalians examine the living while the Casophilians are concerned with the dead.Revivificators - The Revivificators are a Radical faction who descend partly from the Thorians' beliefs. Unlike other factions who seek the resurrection of the Emperor, the Revivificators have few ties with the Adeptus Ministorum. Their goal is the study of the transition of the Human soul to the Warp at the moment of death. Though their studies of the soul are very similar to those of the Casophilians and the Anomolian Beholders, the Revivificators seek a means through which death can be slowed or even halted and ultimately the individual can be resurrected. This peculiar field means that Inquisitors that follow this philosophy tend to be found on the battlefield or in plague areas where they conduct investigations on those that are nearing death. In addition to such locales, they are also common visitors to tombs and mausoleums which leads to a certain amount of disrespect to the practices of the Ecclesiarchy. This has led to Revivificators gaining a reputation as "ghouls" and "ravens" due to the morbid nature of their practices. Revivificators are known to have learned much from the capture of various Aeldari over the centuries. This is because they find the Aeldari spirit to be a fascinating object of study because of that xenos species' ancient ability to reincarnate themselves after death and their other necromantic practices in the wake of Slaanesh's birth and the fall of their lost empire. They have conducted numerous experiments in replicating the Asuryani's practice of capturing a departing soul in a Soul Stone. However, all these attempts have been unsuccessful as Mankind's psychic technology is far inferior to the psychic engineering properties of Aeldari wraithbone. In addition, there are also those who follow this belief who have read Inquisitor Lord Van Hinkel's Treatise on the Soultheft Methods of Eldar Pirates which was written in the 39th Millennium. The detailed text contains a report of the Inquisitor's interrogation of a captured Drukhari which also contained collated information from many other sources which were previously scattered in various libraries and datafiles that were present throughout the Inquisition's fortresses and void stations. The least scrupulous of the Revivificators have attempted to make use of the torturous practices of the Drukhari on Heretics and other criminals. There are few within the Inquisition who are aware of the grisly dungeons that are staffed by Revivificator telepaths and which are wired to arcane machinery for the detection as well as the extraction of psychic energy. The ultimate goal of these Inquisitors is to study the Golden Throne itself and find a means of altering its functions in order for the Emperor's body to be restored. As such, they study not only the passage of a soul into the Warp but also the means through which a corpse can be maintained in a state of readiness for a possible re-infusion of the soul. Access to such knowledge and technologies often mean that the Revivificators live far longer than other Inquisitors. The oldest is Inquisitor Lord Verinath who was shot and killed whilst hale and hearty at the age of seven hundred and sixty-three Terran years.Plutonians - The Plutonians were a Radical sect of the Ordo Malleus of the Inquisition who believed that daemonic possession could be used as a weapon to produce elite Daemonhunters. They formed a close alliance with the Exorcists Chapter of Space Marines and maintained secret facilities within the Exorcists' hidden, subterranean fortress-monastery of the Basilica Malefex on the swampy Feral World of Banish. Within the Halls of Tempering within that facility, it was the Plutonians who carried out the deliberate daemonic possession of Exorcist initiates by Warp entities and then helped them banish those beings a short time later. The process, combined with the unusual resistance of the Exorcists' gene-seed to daemonic possession, created Adeptus Astartes who were incredibly resilient to the temptations of Chaos and extraordinarily capable Daemon-fighters. The Plutonians, as a Radical sect, were well-aware of how their practices could be viewed as extremely heretical by Puritans in the wider Imperium and so they were determined to maintain absolute secrecy at any cost.Unnamed Ultra-Radicals - These Inquisitors, who have no name for their faction that is yet known to the wider Inquisition, are an extreme Radical sub-faction of resurrectionists. They believe that the Emperor's final ascension into the Immaterium, and thus his ability to finally destroy Chaos, requires the death of his body in realspace, which is trapping Him in a weakened form. Needless to say, the Adeptus Custodes are known to ruthlessly hunt down any Inquisitors of this faction whenever they are identified or their activities are detected.