"The body is a model which can stand for any bounded system. Its boundaries can represent any boundaries which are threatened or precarious."
--Mary Douglas, Purity and danger: an analysis of concept of pollution and taboo
"The ordinary margins of the body, those orifices where things enter and leave are places of danger, all the more so when those margins malfunction or when an ordinarily less permeable boundary, the skin, becomes compromised and therefore vulnerable."
--Patrick Nugent, "Bodily Effluvia and Liturgical Interruption in Medieval Miracle Stories."
A manifestation of sympathetic magic was the widespread use of the weapon salve for healing in the 17th century. The weapon salve was applied not to the wound, but to the weapon that caused the wound.