Precognition is an esper ability also called future sight, and second sight. It is a type of extrasensory perception that would involve the acquisition of future information that cannot be deduced from presently available and normally acquired sense-based information. In parapsychology, precognition (from the Latin præ-, "before" + cognitio, "acquiring knowledge"), a premonition (from the Latin praemonēre) and a presentiment are information about future events that is perceived as emotion. It, along with Clairvoyance, Psychometry, Telepathy, and Telekinesis, is one of the 5 attributes that is are measured in their System Scan.
The term has not appeared in the original Japanese version of the Toaru Majutsu no Index light novels.
- Far Vision: An esper ability referenced by Uiharu Kazari in the 8th Toaru Majutsu no Index light novel volume. Little is known about it but it can be assumed that it predicts the future. Interestingly, the kanji used by Far Vision (予知), can be translated as Precognition as well.
- Thoughtography: An esper ability that first appeared in Toaru Kagaku no Railgun, used by Miyama Shaei. The power allows the user to look in the future and allow them to display pictures of it in a medium. The espers can apparently either use analog cameras for the photograph or use a digital camera. 
Non-esper usage of the termEdit
Literally referred in the original Japanese novels as Premonition Perception or sense of foreboding (前兆の感知 Zenchō no Kanchi?) but translated as Precognition in the Baka-Tsuki translations, Premonition Perception is the term used by characters to refer to the skill unconsciously developed by Kamijou Touma through his many battles.
This ability of Kamijou Touma was first speculated by Accelerator, who has been in so many fights that he can subconsciously anticipate the attacks coming his way. Moreover, probably combined with his reflexes and the courage to keep his body and thoughts moving, allow him to judge accurately what to do next. Minute changes in the battlefield, like Misaka Mikoto exuding her electromagnetic field that makes metal items around her resonate, these involuntary movements of hers that not even she can detect, aid Touma in his judgment in where to put his Imagine Breaker. The narrative refers to such phenomena that can be perceived by Touma as "An Involuntary Movements", but implies that its scope differs to the term AIM, and most likely uses it in a literal sense, as in actions that are not voluntary in the part of one who is doing it, like blinking. Mikoto's railgun attack was over three times the speed of sound, and lightning strikes were even faster. Even with a method of defending himself, to be able to time it right was extremely difficult, missing the timing by only an instant would probably result in death. Moreover, it is noted that if he actively tries to take note of these things (referring to the information that he subconsciously takes in and react to), this skill of his is more likely to fail. Furthermore, Lessar noted that even if someone else were to have the same "right hand" like Touma, they couldn't use it half as well as Touma, with his combat skills that accompany it.
Later when fighting Leivinia Birdway, she attacks Touma with countless daggers of water that are packed so fully that it leaves no space for him to hide or evade. But it does not work, for Touma negates a dagger, a dagger that would specifically cause all others to be thrown out of the way after breaking into pieces in a chain reaction that created a blank spot that should not have been there.
It is shown by Rensa that Touma's precognition can be sealed by restricting the information that is shown to him. In the seventh light novel of Shinyaku Toaru Majutsu no Index, she controls her cyborg body in such a way that she completely freezes her facial expression, prevents even the slightest involuntary muscle movements, and times her blinking and breathing to specific set intervals in such a way that Touma will not be able to 'read' her based on those things. However, when Rensa is overloaded because of the presence of Yakumi Hisako in her, and flinches slightly because of her inability to stay still, Touma can easily read her movements and use precognition.
- ↑ 1.0 1.1 Toaru Kagaku no Railgun Episode 14
- ↑ Toaru Majutsu no Index Light Novel Volume 08 Chapter 2 Part 1
- ↑ Toaru Kagaku no Railgun Episode 03
- ↑ Toaru Majutsu no Index Light Novel Volume 22 Chapter 4 Part 5
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 06 Chapter 4 Part 5
- ↑ Shinyaku Toaru Majutsu no Index Light Novel Volume 07 Chapter 4 Part 5