The strength of an image mostly depends  on the sacred nature of the support that hosts it. Archaic cultures invest the rock with a supernatural value. This is recognised by a presumed eternity value and its function as mediator between the sky and the Earth. Already J. David Lewis Williams, in a study of the Kalahari Bushmen (Through the Veil: paintings of St. Rock and the Face of Rock, South Afr. Arch. Bull. 45:5-16, 1990) writes, that we should not consider the surface of the rock as a neutral space ( “Silent support”) that is defined by its form. Lewis Williams learned from the last Bushmen artists how the surface of the rock is treated as a veil, a thin film separating the human world from the one below, home to the spirits of the Earth.

Lewis Williams  states that in order to understand the rock art performance by the San population one has to consider that the bushman artist translates the knowledge held by the community into the images engraved on the rock with full consciousness that the support was a threshold separating the two worlds. It’s not possible to separate this idea from the act that effectively produces the images. Some of the animal figures or monsters are represented between the upper and the lower reality, with some visible parts of the body, as they are this side of the veil, and others not represented at all because these seem to be inside the rock. This way of thinking belongs to the archaic mentality in general, and we can still find it in the popular tradition of the Alpine communities. In Valcamonica (Brescia, Lombardy) the story of the “lady with the goat feet”, was told to frighten hunters and visitors of the forest. According to the story, this woman would have lived inside the rock and she would suddenly come out to eat those who were walking by. To return into the rock, the lady would put her foot over a circular incision that would have opened the passage.

Anodos scene, the ascent of a spirit from the underworld; the spirit rises when he hears the Sileno’s foot hitting the ground. Early Attic Ceramic with black figures, V sec. b.C. (Bèrard, C. Anodoi: Essai sur l’imagerie des passages chthoniens, Inst. Suisse de Rome, 1974.