Telepathy was the extrasensory form of non-verbal communication that was conducted directly from one mind to another. It was derived from telepathic energy. (TNG: "Gambit, Part II") An individual capable of telepathy was known as a telepath, mind reader, or reader of minds. Telepathy existed in various forms across a number of species. A related ability was empathy, the perception of others' emotions.
The vast majority of telepaths could both send and receive messages. (TOS: "The Empath") It was sometimes considered unusual for a telepathic species to experience hallucinations or premonitions. (VOY: "Fury")
According to Neelix, "telepathy is a message, words, a voice." (VOY: "Time and Again") Most examples of telepathy involved the exchange of words, paralleling verbal speech. (TNG: "Ménage à Troi") In other examples, such as the Cairn, telepathy was transmitted via images, allowing for a much faster rate of communication. (TNG: "Dark Page") The living starship Gomtuu could mentally communicate millennia of experiences in a few seconds. (TNG: "Tin Man")
The Enarans could implant their memories into the minds of non-telepaths, allowing those persons to relive their experiences. (VOY: "Remember") While the Ullians performed what they called telepathic memory retrieval, which allowed them to help other individuals recall and enhance moments from their own past. (TNG: "Violations")
Some telepaths could only communicate effectively with their own species. For example, the attempts made by the beings trapped in a Tyken's Rift in 2367 to communicate telepathically caused mental harm to the crew of the USS Enterprise-D and could only be perceived by Betazoids through metaphorical dreams. (TNG: "Night Terrors")
Species such as Betazoids and Vulcans could speak mentally with other telepaths or empaths and also read the thoughts of non-telepathic individuals. Vulcans, however, were rarely seen using telepathy aside from the mind meld. (TNG: "Encounter at Farpoint"; VOY: "Random Thoughts") Betazoids were even capable of perceiving the impulses of non-sentient animals. (TNG: "Pen Pals")
A touch telepath required physical contact to communicate with the mind of another being. The Vulcan mind meld was a form of touch telepathy. (TOS: "Dagger of the Mind") This form of telepathy could be produced between two completely forms of life, such as between carbon-based and silicon-based lifeforms. (TOS: "The Devil in the Dark")
Some species, such as Ferengi and Dopterians, could not be read telepathically, which may be attributed to the structure of their brains. (TNG: "Ménage à Troi"; DS9: "The Forsaken") The Sheliak were so alien that they were incomprehensible to telepaths. (TNG: "The Ensigns of Command")
Telepathy was a natural attribute of some species, present in almost all healthy individuals. In other species such as Humans, telepathy manifested only infrequently, like with Miranda Jones. (TOS: "Is There in Truth No Beauty?") The Aenar were an unusual example of an all-telepathic subspecies within the non-telepathic Andorians. (ENT: "The Aenar")
Over time, telepathy had become the first and natural way of communication for the Cairn, so much so that it later became the only way as they had lost the physical ability to speak. (TNG: "Dark Page")
There were species that possessed extraordinary telepathic powers. The Talosians, Melkot, Botha, and the telepathic pitcher plant could manipulate perception or even trap individuals within fabricated mental realities. (TOS: "The Cage", "Spectre of the Gun"; VOY: "Persistence of Vision", "Bliss"). The Halanans and the Botha had the ability to create telepathic illusions that interacted with the real world like physical objects. (DS9: "Second Sight"; VOY: "Persistence of Vision") The Ocampa could sense impressions from the past, future, and alternate timelines. (VOY: "Time and Again", "Cathexis", "Scorpion") Tarquin's species were not normally telepathic, in fact the odds of being born telepathic on Tarquin's homeworld were one in fifty million. Those that were, were considered to be a threat to the population, and these rare telepaths were sent into exile. These telepaths could read psychic imprints left in objects by those who previously handled them. (ENT: "Exile")
Because Deanna Troi was a Human/Betazoid hybrid, she was not fully considered a "true telepath". According to Data, "Her skills are empathic in nature. She is able to sense the emotions of other beings," but as well, could communicate telepathically with her mother, Lwaxana Troi, as well as her imzadi, William T. Riker. (TNG: "Encounter at Farpoint", "Haven", "Sarek", etc.)
Under rare circumstances, individuals could gain telepathic powers. In 2252, Charles Evans was given telepathy and other powers by the non-corporeal Thasians so that he might survive on their world. (TOS: "Charlie X")
Federation scientists at the Darwin Genetic Research Station on Gagarin IV used genetic engineering to create children with telepathy and telekinesis in the mid-24th century. (TNG: "Unnatural Selection")
Telepathy and technology
A few civilizations developed mechanical telepathy. Landru, a gifted engineer and philosopher, constructed a computer able to telepathically control most of the population of the planet Beta III. (TOS: "The Return of the Archons")
Borg neural transceivers and interlink nodes allowed multiple individuals to share thoughts. (VOY: "Unity", "Survival Instinct", "Counterpoint") Chakotay's interaction with the Borg Cooperative, as per The Doctor's "best guess", was that "the residual neuropeptides heightened his telepathic receptivity." (VOY: "Unity")
The enigmatic Flint built a series of robots that could be controlled telepathically and respond to mental emanations consistent with distress or danger. (TOS: "Requiem for Methuselah") The Romulan telepresence unit relied on telepathy to control drone ships over interstellar distances. (ENT: "The Aenar")
Devices existed to record an individual's thoughts and memories, for example the Federation psycho-tricorder, the Klingon mind scanner, and the Romulan mind probe. (TOS: "Errand of Mercy", "Wolf in the Fold"; DS9: "Inter Arma Enim Silent Leges") The Breen used cortical implants to achieve similar results. (DS9: "'Til Death Do Us Part") The psi-wave devices used by the Prytt could read and transmit thoughts, which had the side effect of enabling "telepathy" between individuals implanted with the devices. When Jean-Luc Picard and Beverly Crusher were telepathically linked, Crusher came to "wonder how true telepaths sift through it all. How can they really get to what someone's thinking if the minds keeps churning all this flotsam to the surface?" (TNG: "Attached")
The Saltah'na created energy spheres that functioned as telepathic archives. The spheres caused those exposed to them to re-enact the thoughts and actions of the individuals stored within. (DS9: "Dramatis Personae")
As of 2368, the Federation had no technology capable of blocking telepathic transmissions. (TNG: "Violations") Still, telepathic suppressors were used by other species, and according to Quark, they were typically bulky. (DS9: "The Jem'Hadar")
Telepathic civilizations often developed a moral code that governed the use of telepathic powers. Several telepathic cultures considered conversing mentally in the presence of non-telepathic individuals to be impolite. (TNG: "Ménage à Troi"; VOY: "Caretaker") Invading another being's mind against their will was considered to be an act of assault comparable to rape. Some, such as the Ullians, codified this into law. (TNG: "Violations"; Star Trek Nemesis) The Mari policed violent thoughts as rigorously as violent acts. (VOY: "Random Thoughts") Information obtained via telepathy was not considered definite evidence in Federation jurisprudence. (TNG: "The Drumhead")
Some species used telepathy as a means of attack, for example the Melkot, the Letheans, and the Botha. According to Spock, "True telepaths can be most formidable" (TOS: "Spectre of the Gun"; DS9: "Distant Voices"; VOY: "Persistence of Vision") The ancient Vulcans developed a psionic resonator, the Stone of Gol, that amplified telepathic energies to kill. (TNG: "Gambit, Part II")
Honesty was embraced by Betazoid culture since the idea of hiding information among a race of telepaths would be functionally impossible; however honest feedback was almost to a point considered rude by other cultures. Lwaxana Troi, on numerous occasions, commented on her befuddlement at the Human practice of fibbing to spare others' feelings or for politeness' sake. (TNG: "Haven", "Dark Page") In something of a similar vein, privacy was a concept unknown to the Cairn before they started to interact with the Federation. (TNG: "Dark Page")
Vulcans and Betazoids established long-term psychic mating bonds; these links could be made with non-telepathic individuals. (TNG: "Haven"; VOY: "Blood Fever"). The non-telepathic Xyrillians also established a mental connection, with the aid of special granules, during their mating process. (ENT: "Unexpected") Telepathy was used ritualistically by joined Trill to commune with past hosts. (DS9: "Facets")
Telepathy has allowed forms of interaction that would otherwise be impossible. The Medusans were a non-corporeal lifeform so different that the sight of them drove Humans insane. Interaction with them was very limited until 2268, when Miranda Jones established a telepathic link with Ambassador Kollos, proving that it could be done. (TOS: "Is There in Truth No Beauty?") The mute Federation mediator Riva was telepathically linked to a Chorus that allowed him to communicate verbally. (TNG: "Loud As A Whisper")
Individuals could be prejudiced against telepaths. (TNG: "Dark Page") The Devore considered trust to be a concept that was alien to telepathic species and therefore deeply mistrusted telepaths, searching all starships passing through their space for them and imprisoning any found. (VOY: "Counterpoint") Tarquin's species regarded telepathic individuals as threats and exiled them to other planets. (ENT: "Exile")
- Extrasensory perception
- Neurogenic telepathy
- Psychoprojective telepathy
- Telepathic mating bond
- Telepathic species
This list contains instances of humans or aliens speaking to each other telepathically, reading someone's thoughts, and reading the images and memories of someone's mind. Although empathy and telekinesis are forms of telepathy, they are not listed here. For appearances of empathic powers and telekinesis please see: Empathy and Psychokinesis, respectively.
- "The Cage"
- "The Man Trap" (Season 1)
- "Charlie X"
- "Where No Man Has Gone Before"
- "Dagger of the Mind"
- "The Menagerie, Part II"
- "Shore Leave"
- "The Squire of Gothos"
- "The Return of the Archons"
- "A Taste of Armageddon"
- "The Devil in the Dark"
- "Errand of Mercy"
- "Who Mourns for Adonais?" (Season 2)
- "The Changeling"
- "Mirror, Mirror"
- "Wolf in the Fold"
- "The Immunity Syndrome"
- "Return to Tomorrow"
- "Patterns of Force"
- "By Any Other Name"
- "The Omega Glory"
- "The Paradise Syndrome" (Season 3)
- "Is There in Truth No Beauty?"
- "Spectre of the Gun"
- "Let That Be Your Last Battlefield"
- "The Lights of Zetar"
- "Requiem for Methuselah"
- "The Savage Curtain"
- "Turnabout Intruder"
- "Where No One Has Gone Before" (Season 1)
- "Loud As A Whisper" (Season 2)
- "Unnatural Selection"
- "The Survivors" (Season 3)
- "The Bonding"
- "Tin Man"
- "Ménage à Troi"
- "Night Terrors" (Season 4)
- "The Drumhead"
- "Half a Life"
- "Unification II" (Season 5)
- "Power Play"
- "Interface" (Season 7)
- "Gambit, Part II"
- "Dark Page"
- "Eye of the Beholder"
- "The Storyteller" (Season 1)
- "If Wishes Were Horses"
- "The Forsaken"
- "Dramatis Personae"
- "Second Sight" (Season 2)
- "The Maquis, Part II"
- "The Jem'Hadar"
- "The Search, Part II" (Season 3)
- "Distant Voices"
- "The Sword of Kahless" (Season 4)
- "The Muse"
- "Broken Link"
- "Things Past" (Season 5)
- "Behind the Lines" (Season 6)
- "Chimera" (Season 7)
- "Caretaker" (Pilot, Season 1)
- "Time and Again"
- "Ex Post Facto"
- "Persistence of Vision" (Season 2)
- "Cold Fire"
- "Flashback" (Season 3)
- "Blood Fever"
- "Scorpion, Part II" (Season 4)
- "The Gift"
- "Random Thoughts"
- "Waking Moments"
- "Infinite Regress" (Season 5)
- "The Fight"
- "Think Tank"
- "Survival Instinct" (Season 6)
- "Unimatrix Zero"
- "Repression" (Season 7)
- Star Trek films:
- "Amok Time" (Season 2, mind meld bonding ceremony is discussed)
Star Trek science consultant and writer André Bormanis has revealed that telepathy within the Star Trek universe works via the "psionic field." According to Bormanis, a psionic field is the "medium" through which unspoken thoughts and feelings are communicated through space. Some humanoids can tap into this field through a kind of sense organ located in the brain (e.g. the paracortex). In the same manner that Human eyes can sense portions of the electromagnetic field, telepaths can sense portions of the psionic field.
Joseph Gatt imagined his character, 0718, to be in telepathic contact with the USS Enterprise's systems at all times through cybernetic implants, more precisely a miniature version of the ship's computer implanted in the back of his head.