From Manhole Cover to Lying Detector: The Curious Tale of Rome’s Mouth of Truth

  Walking around the thousand-year-old city of Rome, you can see magnificent marble buildings and exquisite statues everywhere, which attract tourists to stop and admire. The Church of Cosmedin Santa Maria is one of the attractions with the longest queue of tourists. Although this church, which was built in the 8th century AD, is famous for its gorgeous bell tower and well-preserved medieval murals, most of the tourists who queue up are not here to visit. Coming to the church, their interest focused on the “Mouth of Truth” inlaid on the wall of the vestibule. Tourists are willing to queue up in order to take a photo with it.
  Just looking at the appearance of the “Mouth of Truth”, it is difficult to imagine that it is so popular. It is a marble disk about 1.75 meters in diameter and 20 centimeters thick. It is engraved with a human face with a wide mouth and disheveled beard and hair. The eyes, nose and mouth are all hollow. After two thousand years of vicissitudes, the marble disc has obvious signs of wear and tear. Visitors take turns putting their hands into its mouth, posing either frightened or calm. It turns out that since the 15th century, a “lie detector” legend has been circulating in Rome: if a person lies when he puts his hand into his mouth, or has done something wrong, the stone statue will bite off his hand. Therefore, it is also known as the “Mouth of Truth” and has become famous all over the world, becoming a must-visit “check-in” for tourists when traveling to Rome.
  To modern people, the story of the stone statue biting its hand is absurd, but people in the Middle Ages believed it because at that time, people who put their hands into the mouth of the stone statue were likely to have experienced a “bloody lesson.” It is said that the members of the Inquisition hundreds of years ago often carried sharp tools such as hot irons and knives and hid in a place separated from the stone plate by a wall. There was a hole in the wall connected to the mouth of the stone statue, and some of the inquisitors put their hands into the mouth. Sometimes they will be stabbed to reflect the mystery and authority of the “Mouth of Truth”.
  Has the Mouth of Truth always been used this way since its inception? the answer is negative. If you look closely at the figure above, it is not difficult to find that two crab claw-shaped patterns protrude from its head. This is a symbol of the ancient Greek river god Oceanus. There is also a saying that this pattern represents the sea god. Son of Triton. Both conjectures are closely related to water. Archaeologists believe this likely represents its actual use as a drainage manhole cover. Moreover, the location where the marble discs were stored is also very close to the most famous sewer of Maxima in ancient Rome. This conjecture has basically reached a consensus in the archaeological community. But exactly when it changed from lying flat on the road to standing on the wall is unknown.
  Ancient Rome built a complete water supply and drainage system, covering almost the entire city. The drainage channels of public baths and toilets are directly connected to the city’s sewers, and sewage is collected through the pipes and eventually flows into the Tiber River. Of course, their drinking water and bathing water were not taken from this river, which received a large amount of domestic wastewater, but from spring water drawn from a distance using stone aqueducts. The aqueduct ensured a stable flow rate of water through gravity and siphonage, and continuously transported water to the city of Rome, providing convenience for citizens’ lives and allowing more than a thousand fountains in the city to spray water. The historian Dionysius, author of “Ancient History of Rome”, believed that the construction of aqueducts, sewers and roads reflected the greatness of the Roman Empire. To this day, there are still remaining aqueducts in use in Rome.