A Machine Spirit is a supernatural, animistic spirit believed by the adherents of the Cult Mechanicus within the Adeptus Mechanicus (and, from that source, by most other humans of the Imperium of Man) to inhabit and control any piece of machinery or technology in existence. The functioning, or lack thereof, of any machine is believed to be the result of its spirit's disposition. To keep their Machine Spirits happy and cooperative, operators therefore make numerous ritualised advances to the machinery. These depend on the machine, but in most cases include various maintenance rituals and prayers of function and occasionally also an offering or libation. This is increased if the machine is large and/or important. Machine Spirits are believed to be bestowed by the Machine God and subservient to him. They are in every vital weapon used by those who follow the Emperor. From Bolters to Power Armour, the blessing of the Machine God and his subservient Machine Spirits allows for the Emperor's enemies to be defeated. The term is also applied to the rare instances of machine intelligence allowed to exist within the Imperium, such as the limited artificial intelligences that guide the Space Marines' powerful Land Raider main battle tank and that also sometimes enhance other Imperial devices, particulalrly within planetary Cogitator (computer) networks. Artificial Intelligence Artificial intelligence (also refered to as "Abominable Intelligence" or "Silica Animus" in the Imperium) is prohibited under pain of execution by Imperial edict within the Imperium of Man unless a human mind is combined with it or serves as part of its mechanism (hence the existence of Servitors). This point was made part of the agreement between the Imperium and the Adeptus Mechanicus from the signing of the Treaty of Mars in the 30th Millennium, to ensure that intelligent machines would never again become corrupted by Chaos and rebel against their human masters, as happened during the Dark Age of Technology with the constructs known as the Men of Iron, who launched a star-spanning rebellion against their human creators. However, some machines are allowed a limited form of independant intelligence under the guise of having an especially active Machine Spirit. An example of this is the vehicles of the Space Marines. The Space Marines' Land Raider main battle tank can continue to move and fire, albeit with lesser ability, even if its crew is unable to fight or no longer present. Imperial Titans have particularly complex Machine Spirits and can exhibit complete personalities of their own, though they still require a cybernetic interface with a human Princeps to function at their full potential. source: http://warhammer40k.wikia.com/wiki/Machine_Spirit
Land Raiders are indeed great and mighty machines of the Omnissiah. I do recall once reading a story about a Land Raider that lost its entire crew over the course of a campaign, and decided to roam out on its own. The wondrous machine had snuck through the frontlines of an encroaching Ork Horde, seeking out the Warboss. When it found the warboss, the holy machine executed its prey just as it believed its still-dead crew wanted. Although the machine was destroyed in the ensuing chaos, it was fully honored for its service by the chapter. Machine spirits are indeed real and tangible things.
Does that mean that if an Ork Mekboy believe's in a machine spirit, that spiritless construct GET'S one? If so, and if a spirit already exists inside a machine already, such as some are saying, and this Ork Mekboy believes in a machine spirit does that cause an identity crisis inside the machine? What happens if the construct is then demonically possessed like a Hellkite, Defiler, or other Chaos vehicle? Does it go through a 3 way schizophrenic episode?
I thought if enough orcs believe something it comes true, due to their latent psiconic talent, thats why red vehicles drive faster...or anything the orcs build functions. To topic: I always thought the 'machine spirit' is the part of technology that is not understood. Like the targeting system of a Predator, the operating system of the Landrider etc. They don't know why it does what it does but if you pray and pull that lever, than pray und push that button it works. Or you pray and use some oil on the mechanic system will please the machine sprit so the machine does not break down, aka maintenance of a machine.
Codex: Space Marines 5th editon: Rynn's Might, a Crimson Fist Land Raider that survived the Imperial Fist curse of having a huge chunk of the Crimson Fist chapter die to their own missile during an Ork Waaagh! on their homeworld. It decided to turn itself on and took down the Warboss and a decent chunk of his horde in a single night, before being destroyed as well.
