by primitive people to associate the wearer with some kind of unimpeachable authority, such as a deity, or to otherwise lend credence to the person's claim on a given social role. The oldest masks that have been discovered are 9,000 years old, being held by the Musée "Bible et Terre Sainte" (Paris), and the Israel Museum (Jerusalem). Most probably the practice of masking is much older however – the earliest known anthropomorphic artwork is circa 30,000–40,000 years old. The use of masks is demonstrated graphically at some of these sites. Insofar as masks involved the use of war-paint, leather, vegetative material, or wooden material, such masks failed to be preserved, however, they are visible in paleolithic cave drawings, of which dozens have been preserved. At the neanderthal Roche-Cotard site in France, a flintstone likeness of a face was found that is approximately 35,000 years old, but it is not clear whether it was intended as a mask. In the Greek bacchanalia and the Dionysus cult, which involved the use of masks, the ordinary controls on behaviour were temporarily suspended, and people cavorted in merry revelry outside their ordinary rank or status. René Guénon claims that in the Roman saturnalia festivals, the ordinary roles were often inverted. Sometimes a slave or a criminal was temporarily granted the insignia and status of royalty, only to be killed after the festival ended. The Carnival of Venice, in which all are equal behind their masks, dates back to 1268 AD. The use of carnivalesque masks in the Jewish Purim festivities probably originated in the late 15th century, although some Jewish authors claim it has always been part of Judaic tradition. The North American Iroquois tribes used masks for healing purposes (see False Face Society). In the Himalayas, masks functioned above all as mediators of supernatural forces. Yup'ik masks could be small finger masks, but also masks hung from the ceiling or carried by several people. Masks have been created with plastic surgery for mutilated soldiers. Masks in various forms – sacred, practical, or playful – have played a crucial historical role in the development of understandings about "what it means to be human", because they permit the imaginative experience of "what it is like" to be transformed into a different identity (or to affirm an existing social or spiritual identity). Not all cultures have known the use of masks, but most of them have.