The pedagogical pilgrimage to retributive hell is probably the most detailed religious phenomenon common to the greatest number of major Eurasian religious traditions. No matter whether the visitor was named Muhammad or Mulian, Vipashchit or Viraf, St. Patrick or Moses, Odysseus or Dante, the protagonist was led through the grisly horrors of hell so that he (or, more rarely, she) could return to the living and warn them to live moral lives. Why was this religious phenomenon so widespread? It may be because of cross-cultural fertilization (with the Chinese vision of hell originating in India, possibly by way of Persia), because of independent "de novo" origination, or because of a combination of the two.
Among the Chinese pedagogical pilgrimages, that of Tang Emperor Taizong (r. 627-50) is one of the most famous. In a later version of the narrative preserved in The journey to the West, the Jade Emperor of the heavens had ordered the execution of a river dragon who had shirked his duties, and this dragon asked Emperor Taizong to intercede on his behalf. Wanting to be merciful, the human emperor had promised to do so but, despite his best efforts, was unable to prevent the dragon from his just beheading. Regardless of tradition, these pedagogical pilgrimages regularly address this conflict between justice (karma, retribution for sins, etc.) and mercy (the rescue by a bodhisattva, the forgiveness of sins, etc.).
Emperor Taizong then fell into a delirious dream-like state during which the executed river dragon dragged him down to the hell courts to answer for his failed promises. The emperor was cleared of any wrongdoing, but while he was there, he witnessed the spectacle of hell's horrors and was told to record it for posterity so that the living would know what was in store for them if they did not mend their ways. Thus Emperor Taizong, whose personal name was Li Shimin, often appears standing next to the beheaded dragon on the first hell scroll, serving as a kind of seal of approval testifying to the veracity of these images.
This first hell was regularly portrayed as a preliminary realm where a liftetime's guilt and good deeds were reviewed and where all due tortures and rewards were then assigned. The karma mirror, often positioned on a high terrace, revealed all of one's misdeeds as the self encountered itself as other in a kind of reflexive act. The best of the best at this point were here allowed to leave the endless cycle of death and rebirth, exiting to the Western Paradise of Amitabha Buddha. (Note that, because late imperial Chinese hell was syncretic in nature, the guides are here leading Confucians, Daoists and Buddhists alike over this bridge to the western lands.)
