"Hail the Omnissiah! He is the God in the Machine, the Source of All Knowledge."
- — Magos-Lector Vad Kapellax, at the first Convocation of the Lathes
The Machine God, also known as the Omnissiah or Deus Mechanicus, is the supernatural entity worshipped by the Tech-priests and other servants of the Adeptus Mechanicus as the embodiment and bestower of all knowledge and technology in the universe.
For many in the Imperium of Man, this belief conflicts with the orthodox theology of the Imperial Cult where the only god of humanity is the Emperor of Mankind. But since the Adeptus Mechanicus is vital to the survival of the Imperium, conflict over this issue is often avoided by the Mechanicus' willing conflation in its theology of the Machine God's avatar in the physical world, the Omnissiah, with the Emperor Himself.
This compromise truly satisfies neither believers in the Cult Mechanicus or the Imperial Cult, but it keeps the peace between the two faiths and the wider Imperium functioning.
The Cult Mechanicus, the religious hierarchy of the Adeptus Mechanicus that upholds the worship of the Machine God, believes knowledge to be the manifestation of divinity, and holds that anything embodying or containing knowledge is holy because of it. The supreme object of devotion is therefore the omniscient Machine God, an imminent, omniscient and omnipotent deity that governs all machinery and knowledge in the universe.
Generally, this deity is held by orthodox believers to be an aspect of the God-Emperor of Mankind in the form of the Omnissiah. The Omnissiah, the physical avatar of the Machine God in the universe, is believed to be friendly to humanity as His chosen people, and to be the originator of all human technological and scientific knowledge. There are many members of the Mechanicus who have doubts about whether the Omnissiah and the Emperor are actually the same being. Many heretical cults within the Mechanicus hold that the Omnissiah may not yet have revealed Himself. It was similar beliefs that led to the outbreak of the Schism of Mars and the formation of the Dark Mechanicus during the Horus Heresy.
The third member of the Cult Mechanicus' trinity is the Motive Force. The Cult Mechanicus believes that all life and motion owes its continued existence to the universal power that is the Motive Force. The Motive Force finds its fullest expression in the animistic Machine Spirits, who are believed to inhabit all machinery and which must be appeased before a piece of technology is used or repaired, lest the machinery fail.
The Quest for Knowledge
The ultimate goal of the Cult Mechanicus is to understand and fully comprehend the glory of the Machine God. The communal and personal attempt at this form of enlightenment is known as the Quest for Knowledge. The Cult believes that all knowledge already exists in the universe, and it is primarily a matter of time before it can be gathered together to complete the Quest.
The Cult is therefore theologically disinclined to perform most basic scientific research and development. Despite this, some original scientific research does continue on Mars and the other Forge Worlds of the Imperium, enough to keep Imperial technology advancing steadily, if extremely slowly. The faith of the Cult is defined by a series of sixteen precepts, known as the Sixteen Universal Laws, which have been divided into two sets of eight precepts known collectively as the Mysteries and the Warnings, which are listed below.
The Mysteries of the Cult Mechanicus
- Life is directed motion.
- The spirit is the spark of life.
- Sentience is the ability to learn the value of knowledge.
- Intellect is the understanding of knowledge.
- Sentience is the basest form of Intellect.
- Understanding is the True Path to Comprehension.
- Comprehension is the key to all things.
- The Omnissiah knows all, comprehends all.
The Warnings of the Cult Mechanicus
- The alien mechanism is a perversion of the True Path.
- The soul is the conscience of sentience.
- A soul can be bestowed only by the Omnissiah.
- The Soulless sentience (i.e. Artificial Intelligence) is the enemy of all.
- The knowledge of the ancients stands beyond question.
- The Machine Spirit guards the knowledge of the Ancients.
- Flesh is fallible, but ritual honours the Machine Spirit.
- To break with ritual is to break with faith.
The Void Dragon
According to the beliefs of the Cult of the Dragon, the Machine God may actually be the C'tan shard known as the Void Dragon, an ancient alien entity of immense power. It is imprisoned in a Necron-built Stasis Tomb beneath the Noctis Labyrinth on Mars. The mighty C'tan was imprisoned by the Emperor Himself before He even publicly emerged to found the Imperium of Man on Terra and initiate the Unification Wars over 10,000 Terran years ago. At that time, the Emperor proved unable to kill the C'tan even with His great power, and so He imprisoned it beneath Mars so that the powers of the C'tan, though passive, would cause the Adeptus Mechanicus to emerge, which the Emperor needed as support for his future Great Crusade to reunite Mankind. This so called "Grand Lie of Mars" is buried deep beneath the sands of the Red Planet in an underground complex which is actually the Void Dragon itself.
The truth of this seemingly insane legend has gained more credibility since the mass awakening of the Necrons across the galaxy. It is said that a small number of Necron forces managed to breach Imperial defences in the Segmentum Solar and land on Mars itself after destroying some of the Noctis Labyrinth Mine Complexes.
Upon landing, countless Mechanicus Skitarii and Titan forces quickly despatched the small Necron expeditionary force. Although the Necrons were eliminated, their purpose on Mars remains unknown to the Imperium. More striking is the fact that they breached vast areas of Imperial space (including the Segmentum Solar itself) undetected. The Mechanicus enforced a Perdita zone around the entire Noctis Labyrinth after this incident, presently still enforced by an entire Skitarii Legion.
- Codex: Adeptus Mechanicus (8th Edition), pp. 44-45, 80
- Codex: Adeptus Mechanicus - Cult Mechanicus (7th Edition) (Digital Edition), "Fulgurite Electro-Priests," "Corpuscarii Electro-Priests"
- Codex Imperialis (2nd Edition), pp. 41-42
- Index Astartes, "Cult of the Machine God"
- Mechanicum (Novel) by Graham McNeill
- Warhammer 40,000: Rulebook (4th Edition), pp. 120-122