Reading Thoth 78 (問答型思考補助式人工知能 (リーディングトート78) Mondō-Gata Shikō Hojo-Shiki Jinkō-Chinō (Rīdingu Tōto 78)?, lit. "Discussion-type Thought Assistance Artificial Intelligence") is an artificial intelligence that is introduced in Shinyaku Toaru Majutsu no Index that is apparently is for the sole purpose of being used by Aleister Crowley.