Mentalics refers to those with the ability to read and shape the minds of others. All members of the Second Foundation were Mentalics, and used their abilities to aid the Seldon Plan whenever necessary. A Mentalic robot is featured as early as the short story "Liar!" in I, Robot; Mentalic humans are not introduced until Second Foundation.


The first known Mentalic robot, RB-34, also known as Herbie, was manufactured accidentally in the year 2021. While the roboticists at U.S. Robots and Mechanical Men investigated how this occurred, the robot told them what other people were thinking. The First Law still applied to this robot, and so it deliberately lied when necessary to avoid hurting their feelings and to make people happy, especially in terms of romance. However, by lying, it was hurting them anyway. When it was confronted with this fact by Susan Calvin, to whom it falsely claimed her coworker was infatuated with her, a particularly painful lie, the robot experienced an insoluble logical conflict and became catatonic. Her last word to the robot was "Liar!", a myth that over the thousands of years to come spread as a myth throughout the Spacer worlds, as part of Susan Calvin's general depiction as a "demigod".

One Mentalic, Marlene Fisher, existed in 2236. Her powers allowed her to communicate with the planet circling the Nemesis star. This story survived to Imperial times.

From 2021 until the 4600s, no known Mentalic robot was created. However, in the late 4600s, young Vasilia Fastolfe's tampering with the robot R. Giskard Reventlov, created by her father Han, made it into a Mentalic. In 4724, Giskard discovered that Kelden Amadiro was experimenting on R. Jander Panell, the second humaniform robot ever, created by Han, to find the secret of humaniform robots. He used his telepathic powers to destroy Jander, not only to thwart these attempts but to get renowned detective Elijiah Baley called to Aurora to allow Earthpeople to colonize the Galaxy. Baley was called to Aurora to solve this "roboticide" and exposed Amadiro, coming to the conclusion it was merely chance that Jander was deactivated. Secretly, however, he confronted Giskard who admitted it was him to Baley and then his partner, R. Daneel Olivaw, the remaining humaniform robot. After Amadiro's exposure, Fastolfe and Amadiro came to an agreement where Earthpeople could colonize the Galaxy, and Amadiro would find the secret for humaniform robots. On parting Aurora, Baley told his love Gladia Delmarre to trust Giskard.

Giskard became important again in 4922. A seventh-generation descendant of Baley's, Daneel Giskard "D.G." Baley, gained Gladia's help in visiting Solaria, to investigate the destruction of several "Settler" spaceships that made landings there, and to capture the presumably unsupervised robots. Gladia was accompanied by Giskard and Daneel. At the same time, Daneel and Giskard were engaged in a struggle of wits with Fastolfe's rivals; they discovered Amadiro's plan and attempted to stop him, but were hampered by the First Law of Robotics, which prevented them from a direct attack on Amadiro. Daneel and Giskard, meanwhile, had inferred an additional Zeroth Law of Robotics: "A robot may not injure humanity, or, through inaction, allow humanity to come to harm". This could enable them to overcome Amadiro, if they could use their telepathic perception of humanity to quell the inhibitions of the first law. When Vasilia accused Giskard of telepathy, earlier created by herself, Giskard was compelled to manipulate her mind to make her forget about his telepathic powers. The two robots located Amadiro and Mandamus on Earth, at the site of Three Mile Island in Pennsylvania. After Amadiro admitted their plans, Giskard altered Amadiro's brain using the newly created Zeroth Law, but in so doing, threatened his own. Now alone with the robots, Mandamus claimed that his intentions were to draw out the radioactive catastrophe over many decades, rather than the mere years that Amadiro wanted, and Giskard, believing it best for humanity to abandon the Earth, allowed Mandamus to do this, and deprived Mandamus of the memory of doing so. Giskard predicted, correctly, that by forcing humanity into leaving the Earth, vigor would be reintroduced into mankind and the new Settlers would populate space until all the governments of the interstellar colonies formed a "Galactic Empire". Under the stress of changing the course of humanity against First and Zeroth Laws, R. Giskard himself suffered a soon-fatal malfunction of his positronic brain and conferred his Mentalic powers upon R. Daneel.

From that point on, Daneel used his Mentalics to guide humanity, eventually manipulating the creation of a Galactic Empire. He created the superorganism, Gaia, comprised of Mentalics all connected.

For thousands of years, Mentalics had no importance, except that Daneel, under the guise of Eto Demerzel, used his powers to orchestrate Hari Seldon into beginning psychohistory. Then, in 12,052 GE, Hari Seldon, after Wanda showed signs of mental abilites, and learning of the Nemesis story, theorized about the Mentalics to his adopted son Raych.

"I have a notion that youngsters are born-not often, but occasionally-with such mental abilities, but that, in general, it merely gets them in trouble and they learn to mask it. And as they grow up, their ability, their talent, is buried deep within their minds-sort of an unconscious act of self-preservation. Surely in the Empire or even just among Trantor's forty billion, there must be more of that sort, like Wanda."

He went about finding these Mentalics. He had no luck until six years later, when he and Wanda found the Mentalic Stettin Palver, who had joined Seldon's psychohistory project. Wanda and Stettin then went about finding others together, beginning with psychologist Bor Alurin. Leaving Seldon, Wanda and Stettin set up the early Second Foundation on Trantor, comprised of Mentalics. Bor Alurin was the only Mentalic who joined the First Foundation, as a mole to oversee things.

When Trantor was sacked, Stettin's descendant Preem helped it rise from the ashes. The Second Foundation guided the First across the centuries. In 300 FE, the Mule searched for it but was trapped by them and his mind altered. In 378 FE the First Foundation thought they had destroyed it, when in reality they had not. Golan Trevize was sent looking for it in 498 FE. He gound it as well as the Gaia superorganism Daneel had created thousands of years ago, also comprised of Mentalics. Gaia altered the First Foundation's Mayor's mind so it did not know of the Second Foundation's existence once again.

Trevize chose for the galaxy-wide superorganism Galaxia, made up of Mentalics connected in one being. This was the ultimate fate of humanity. Daneel, now retired and on the Moon, decided to merge with a human, Fallom, and oversee its creation without the Three Laws.