Inquisitional Philosophy: Autospiritines
The Autospiritines are a divisive group of Inquisitors associated with Puritanism, though one would not know it for how they are despised by the Monodominants and Thorians. Indeed, it perhaps only the staunch desire of Imperial harmony from the Amalathian power bloc that prevents the Autospiritines from being cast out into the perilous state of Radicalism, or perhaps to darker places still.
The source of this hatred, and the core of the Autospiritines' beliefs, is due to their association with the Adaptus Mechanicus and the advancement of the doctrines of the Machine Cult. Despite the popular assertion, few Autospiritines are actually members of the Mechanicus (and fewer still, as they are often accused, work against the Inquisition for them), but mostly are lay adherents who came to respect or revere the teachings of Mars during their time as acolytes or in the uncommon instances of cooperation over conflict between the Inquisition and the Mechanicus. More traditional tech-priests spurn the adoration of the Autospiritines, but they are nothing if not versed in interaction with machine cultists, and more often than not can overcome the long-standing barriers between the two groups, at least on the Mechanicus' side.
It should come as no surprise then, that the primary belief of the Autospiritines is advancing the Quest for Knowledge through ceaseless search for the holy grail of all technologies: The Standard Template Constructor. This, they claim, is the Omniessiah's promised salvation for humanity, and that once they discover it all the enemies of the Imperium will be swept away. Further, Autospiritine Inquisitors seek mysteries and truth through the holy knowledge of the machine spirits. Many of mankind's more venerable machines have seen millennia of knowledge and history pass by their immortal circuitry, and accessing this knowledge can be a tool of incredible power. Many who associate with these Inquisitors note that their possessions often seem almost protective of them; telling stories of impossible bolter shots and ship machinery butchering boarding parties.
Autospiritines are a notably anti-resurrection group within the Inquisition. It is their belief that the Emperor's ascension is not something to be interfered with, and that he embodies an ethereal form intentionally. Some Autospiritines take an eschatological position that the Emperor will return in his true form, as a fusion of man and machine, only when the Imperium finds a complete STC. It should be noted that the Autospiritines are perhaps some of the only people in the entire Imperium who do not just grudgingly accept, but actively support the doctrine of the Emperor-as-Omniessiah.
In the present, the Autospiritines try to lessen the rift between the Imperium proper and the Mechanicus (a task for which they receive rare direct support from the Amalathians) on the basis that this will strengthen humankind. Their most common projects are to achieve interplay between the Imperial Guard and the Skitarii, as an example of the power they can wield when not in conflict. This ties back to their belief in the weakness of flesh, and though not quite as extreme as that espoused by the Magi, it is still a frequent event for an Autospiritine to reject rejuvenat treatment and non-cybernetic healing in favor of machine replacement long before other Inquisitors.
And there you have it, Mechanicus Inquisitors.