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A Mentat was a profession or discipline that was developed as a replacement to the computers and thinking machines following the Butlerian Jihad that banned the creation of machines in the human mind's image, just as the Spacing Guild and the Bene Gesserit took up similar functions.

The name "Mentat" is derived from mentis, meaning "of the mind" in Latin, an ancient Terran language. The founder of the Order of Mentats, a logician and philosopher of interstellar repute, coined the term to refer to those fully trained and proficient in the techniques he prescribed for the Order.


In the aftermath of the Jihad, computers and other forms of thinking technology were made obsolete due to the OCB's commandment against thinking machines, "Thou shalt not make a machine in the likeness of a human mind", and, at the same time, the anti-AI laws had been placed in effect; the punishment of owning such AI device or any kind being immediate death.

The first Mentat[]

Gilbertus Albans (1192 AG-1294 AG) was a Septimian philosopher and logician who conceived a program of far reaching importance one spring morning in 1231 AG during some leisure time reading on the Butlerian Jihad. It occurred that the legendary computers had been built by humans and it seemed unlikely to him that they had possessed capacities beyond those of the trained human mind. Over the next few years he devised a plan of study for the production of human computers which he named Mentats and recruited students for the program. During the reign of Mikael I the Builder (1234 AG) the Order was formed.

The early Order located on Septimus consisted of three ranks of adepts: Memorizers, Processors and Hypothesists. The infant order was found often in financial difficulties but Albans allowed his trainees to publicize Mentat abilities and math practice and those who passed through all three ranks were allowed to serve. This led to the relocation of the Order House. Albans would take to travel in exhibiting their skills in order to advertise his program.

Some tragic incidents on Septimus concerning his Processors, including the incident where they were killed in the arena, almost led to the disgrace of the Order and Albans saw that at worst the Order risked destruction and at best faced public ridicule. He contracted with the Guild to relocate to Tleilax (1246 AG). For a percentage of tile profits, the Tleilaxu agreed to supply the Order with military protection, beginning an association with regrettable consequences centuries later.

Albans trained a number of Hypothesists there and he undertook an effective campaign to persuade CHOAM directors and managers of the extraordinary value of Mentats the living computers.


Grodon Orpar Playt III, ex-director of CHOAM, persuaded Albans to expand the program to meet the needs of government leaders Playt proposed the three senior ranks of Generalist, Simulationist and Advisor, and extended the training program to accommodate thee new ranks in a thorough revision of Albans' Mentat Handbook. His revision remained almost unchanged for millennia thereafter

The Order grew slowly at first, but ever more quickly as CHOAM executives realized the worth of Mentats. Their rigorous discipline, commitment to logic and avoidance of emotion provided for peaceful and orderly expansion of the Order. By 1625 AG the Order House reached its optimal size accurately predicted by Albans

Infants and toddlers: 225
3 to 6 years old: 440
7 to 10 years old: 400
11 to 13 years old: 280
14 years old: 90
15 years old: 80
Minor ordinaries
Memorizers: 60
Procssors: 55
Hypothesists: 50
Major ordinaries
Generalists: 10
Simulationists: 6
Advisors: 4

The Order also comfortably supported a staff of 1700 at the House and a field staff of 200 in its auxiliary The Friends of the Order of Mentats.

Because of this success and secrecy, for centuries the Order grew rich as well as its Tleilaxu protectors. Perhaps from this wealth came the investment capital for their programs in biogenetic engineering. Others suggest that this led the greedy Tleilaxu to attempt the production of mentats by other means.


During the unprecedented economic growth of the Imperium particularly under Avelard II (r. 1624 AG-1647 AG) and under severe political pressure Avelard was about to sending troops to Tleilax to force the Order to expand its training program. Proctor Makarfo Bonn resisted the demands to alter the size pace or quality of the Order s training efforts and finally persuaded Avelard that neither Imperium, CHOAM, nor Landsraad would gain from watered-down Mentat training. The Tleilaxu claimed part credit for the Emperor's forbearance. After the crisis they released the news that they had threatened to resist the invasion with force (this claim has met with uniform skepticism if one considers the united Sardaukar and Landsraad strength against the Tleilaxu)

The Order faced significant problems from radical neo-Butlerians in whatever form that fanaticism emerged over the centuries. Among the most violent were the Pularsaman Leftists, who considered Mentats as traitors who had turned their minds into organic machines. The terror of the Pularsamans was directed against the individual Mentat, though, and assassination-not mass force-was their favored tactic.

The Tleilaxu could not guarantee the security of Mentats scattered in ones and twos over a thousand worlds and the necessity of defense led to the inclusion of martial arts into the curriculum. The Ginaz School of Master Swordsmen, for example provided training to Advisor rank Mentats, thus helping to create the specialization of Mentat Assassin. By the tenth millennium, Mentat Assassin such as Thufir Hawat or Piter de Vries were sine qua non for a major house with higher aspirations.

Other specializations were appearing at this nexus of powerful political forces; the ghola Duncan Idaho presented to Muad'Dib by the Tleilaxu was a Zensunni philosopher-Mentat. Dondar Kooreeg theorizes that the ghola's Mentat training was crucial to his unprecedented recovery of his pre-ghola identity.

The truly regrettable waste in Mentat specialization was the failure to link Mentat training with either the Spacing Guild or Bene Gesserit programs. All such attempts (and many were extended) met with hostility.


One society that welcomed Mentat experience was the Tleilaxu They boasted that through their experiments in controlled mutation, they had combined Mental ability with specially tailored accomplishments (or perversions) of their own. One result was the notorious KMP ("Killer-Mentat Program")

Albans had warned against combining Mentat training with any form of specialization, but with the passage of millennia his admonitions were ignored, most disastrously by Proctor Hiebines XI in 10054 AG. He agreed with the Tleilaxu to supply third and fourth-rank Mentats for experiments aimed at achieving a genetic sub structure upon which to ground a streamlined Mentat training program. Although the plan was sold to Hiebines as a low-risk way of multiplying well-qualified Mentats, its ultimate result was the destruction of the order. The Tleilaxu gained access to the secret Mentat programs but their products were utter failures-rebellious against their masters, disloyal to the Order, and guilty of heinous miscalculations. Tleilax Mentats, were worse than useless, causing the reputation of the Order to plunge and even reliable Mentats to be mistrusted. From this catastrophe arose the fear of "Twisted Mentats/DE"

During the reign of God Emperor[]

The Order of Mentats never regained its former prestige but still enjoyed limited respect in some sectors until the reign of Leto II Atreides.

Along with the Guild and the BG, the rise of Leto II to the title of God Emperor brought with it new problems for the entire Mentat order. Leto's extremely long life, coupled with his goal to realize The Golden Path in order to ensure humanity's survival, saw him hoard the Spice Melange seemingly without much concern for short-term problems. During the first thousand years of that Emperor's reign his Fish Speakers and planetary administrators systematically promoted Mentat-doubt. This scheme, with Leto's other plasteel-fisted policies, led to a diminished need for Mentats and greater public suspicion of their contributions

During the 3,500-year rule, the Mentat order formed a nucleus of independent opposition. They, like many other groups, were dispersed in the Scattering. Mentats were outlawed by God Emperor Leto II, and any renegade training schools crushed.

Leto's aim appears to have been the gradual destruction of the Order, beginning by progressive weakening it; his many Duncan Idahos were charged with surveillance of all known Mentat Advisors, lower ranking Mentats were required to register with planetary governors and secure special permission to travel between planets; the Guild (fearing loss of its spice allowance) often refused even reasonable Mentat requests. This harassment climaxed with the infamous report of Duncan Idaho-11736, which accused the Order of responsibility for the disasters that befell many Houses Major at the end of the Corrino dynasty. In carefully orchestrated horror at the report Leto outlawed Mentat training in 11745 AG. Within 90 years all known Mentats, including those in probationary training had died, and the Fish Speakers sealed the vacant Order House on Tleilax for 200 years.

The House was later reopened as a museum, but Leto did not extend his toleration of Museum Fremen to allow the establishment of Museum Mentats. Nevertheless, when the public was permitted access to the House, no papers, manuals, or instructional guides were found among the records. To date, the only Mentat material found among the Rakis Hoard is a transcription of a mutilated, partial copy of the Mentat Handbook. There remains the possibility, never actually confirmed or denied, that the Bene Gesserit had stolen the missing material to incorporate Mentat training into their own programs

By an irony of history, Leto II was once forced to rely on Reverend Mother Anteac, who, contrary to his order, was alleged to be a fully trained Mental Advisor. In the last year of his life, Leto asked Anteac to undertake a journey to Ix where she died without reporting to her Mother House either the nature or the result of that mission. The irony is double if indeed Anteac, a woman, was the last of the Mentats.

Mentat training[]

The role of Mentat required a certain degree of mental ability, and strict mental conditioning. Though not all Mentats were of equal ability, all were typically able to guarantee employment with one of the power brokers of the Known Universe. Prospective Mentats were required to have both the inner predisposition necessary to make the training effective, and what Albans referred to as "a call to reason" to make the discipline tolerable. Given these qualities, following a solemn decision and much preliminary training, the initiate would be welcomed into the actual program as a novice Memorizer

Training began as early as possible, even in infancy if strong potential was noted; this stimulated sensory awareness through sound, color, texture odor, and taste, kinetics's awareness through spinning, rocking warmth, cold, emotional awareness through fear, joy, anger, love hate, and security.

During childhood, the future Mentats developed mentally and physically in rigorous, year-round programs as a means to broaden the youngster's cognition and to resist specialization. Severe punishment was used for neglecting one study in favor of another "Everything is important, and nothing is more important than everything" was the motto of the Mentat training school

A strict and unforgiving disciplinary code promoted Albans' goal that every child be completely self-directed by 15. Campus construction and maintenance, the evening silence, the weekly fast, all tasks performed by lowerclassmen and directed and enforced by upperclassmen, who punished breaches with a severity they had learned in their turn from their predecessors. Sports developed strategy as well as physical skill, some, long distance running, for example aided the disciplinary code and the six-day-a-week curriculum in either producing a fully ready candidate for the novitiate or in turn, washing out of the program

In the final preparatory year, at about 15, students were grounded in prepositional and predicate logic, inference, modal deduction, transinfinite induction, statistics, multivalent analysis, conceptual synthesis, N-dimensional geometry, formal linguistics, and transcendental phenomenology. These studies provided the mental linkages to accept subsequent Mentat training, should the student succeed in mastering them

Assuming the success of the early conditioning and education, age 15 was the year of decision, of sponsorship as a Mentat candidate. The applicant's predisposition-his commitment-had been amply demonstrated by 15, leaving only his "calling' to be heard to gain acceptance. The applicant secluded himself and meditated, awaiting the call. For some it never came. For others the vocation grew from patient deliberation For a few, a flash from the core of being cried "Yes" to the opportunities and dangers of life as a Mentat. Those who never received the call were not disgraced and served the Order in a variety of ways-as teachers of the young, administrators, or in the auxiliary, The Friends of the Order of Mentats. But if the call did come, the Order rejoiced, other applicants and their mentors pledged to help and support the Called One throughout his life whatever his final progress on his path through the ranks of the Order

Use of Mentat[]

Unlike computers, Mentats were not simple human calculators. Instead, the exceptional cognitive abilities of memory and perception were the foundations for supra-logical hypothesizing. Mentats were able to gather large amounts of data and devise concise analyses in a process that goes far beyond logical deduction: Mentats cultivate "the naïve mind", the mind without preconception or prejudice that can extract the essential patterns or logic of data and deliver, with varying degrees of certainty, useful conclusions. Indeed, this ability saw many military commanders and political leaders undergo some form of Mentat training. Examples of this include Paul Atreides, Miles Teg, and most of the Duncan Idaho gholas. A few individuals, such as Thufir Hawat, had sufficient innate Mentat abilities to be an exclusive advisor to House Atreides.

The ability to become a Mentat was a talent limited to a small number, thus those with the discipline were prized in whatever role they choose. There are also varying degrees of ability. A Mentat's capabilities can be greatly increased by taking sapho juice, but using it leads to addiction. Sapho is extracted from the root of the Ecaz tree and its use doubles or even triples the Mentat's immense processing power. However, repeated use turns the user's lips a shade of red.

A Mentat adept could be characterized as

  1. a human in the generic, Bene Gesserit sense (although the Sisterhood would deny it violently), as "an animal with reason and logic',
  2. an expert in all methods of logic and inference,
  3. a conceptual generalist, in contrast to specialists in narrow areas, and
  4. one possessing a quasi-truth-sense based not on prescience but on inference

They were used extensively by the Great Houses, primarily as political advisors before the rise of God Emperor Leto Atreides II to the throne. Thanks to their vast memories and ability to organize huge amounts of data they often provided valuable insights that would otherwise be lost. Limited Mentat training was also used to augment individuals destined for other political or military roles.

Mentats were also used, to a lesser extent by the Bene Gesserit. Though unlike the Great Houses, all Bene Gesserit Mentats were pre-conditioned Reverend Mothers. For thousands of years, society thought of Mentats as the embodiment of logic and reason.

The Mentat adept was capable of achieving remarkable inferential linkages and gestalten spasms of pure insight, but usually only when deep in a Mental-trance. Some allege that the so-called Mentat-trance was merely a dramatic device used to make the Mentat appear more impressive But the subjective reports of scores of Mentats and the objective evidence of hundreds of studies all point to the authenticity of the trance. The eyes glazed, the voice-intonation flattened and awareness appeared to be turned inward.

Perhaps because of their apparent need to rely on this isolating trance-state for higher percentages of accuracy, Mentats historically failed as leaders. No significant Mentat succeeding as an entrepreneur, a politician or a soldier. Some have even argued that Paul Muad'Dib himself was partly unsuccessful because he tried too often to approach complex social and political problems only as a Mentat. But he never officially studied in an Order-approved program. Leadership is a matter of temperament, not reasoning ability and the effective leader must often make intuitive decisions in the absence of complete data. Mentats-human computers-are trained to avoid such judgments when at all possible and a good leader acts because a decision must be made; a Mentat delays because a decision should not be made

Mentats were required to operate within an ethical framework, which for some purposes was not desired. Thus, the Bene Tleilax were known to condition some Mentats to be 'twisted'. These individuals, such as Piter de Vries, were able to compute trends free of any ethical restraints or limitations.

Structure and order[]

From the earliest days of the Order, Albans saw little connection between skill as a leader and excellence as a Mentat/ Therefore, in naming the six ranks of Mentals, Albans avoided titles that suggested action ("president, director, manager" and the like) in favor of titles that emphasized processes and relationships.

The three Junior Ranks were named, in ascending order, Memorizer, Processor and Hypothesist.

The first Mental Hypothesists went to CHOAM, but Albans realized that they could be remarkably useful to governments, not just in the bureaucratic tasks they could fill. Planetary governors, heads of Houses, generals, and politicians would all welcome reliable, objective, loyal, discreet, and accurate advisors, and the existing Mentats could not fill this need.

Grodon Orpar Playt III, after joining the order revised the Mentat Handbook to include three Senior Ranks about seventeen years after Albans first presented his Hypothesists to the worlds. These were Generalist, Simulationist, and Advisor. Playt's Handbook was used, virtually unchanged, through the history of the Order of Mentats.


Memorizer Babble, Processor naivete, and Generalist pride were common problems experienced by the junior ranks. But other conditions could impair a Mentat's abilities such as Mentat Freeze, Sapho addiction, Rhajia and Verbal Dependence.

The Mentat mantra (From David Lynch's movie only)[]

"It is by will alone I set my mind in motion. It is by the juice of Sapho that thoughts acquire speed, the lips acquire stains, the stains become a warning. It is by will alone I set my mind in motion."

Known Mentats[]

Exclusive Mentat Advisors[]

Lesser trained Mentats[]

Behind the scenes[]

The exact origin of the Mentat's order is outlined in Frank Herbert's Chapterhouse: Dune novel and it is attributed to Gilbertus Albans. In the Legends of Dune novels by Brian Herbert and Kevin J. Anderson Albans was trained by the thinking machine, Erasmus.