to ward off spirits. However, Douglas states that it is not enough to limit the differentiation between European rituals and primitive ritual to simply hygienic benefits. She claims that the modern conception of dirt is synonymous with the knowledge of germs and bacteria;It is difficult to think of dirt except in the context of pathogenicity.If one removes the notions of bacteria and hygiene from the concept of dirt, all that remains is the symbolism of dirt;The product of a systematic order and classification of matter. Dirt as disorder in the symbolic structure Douglas then proceeds to establish the notion that humans have a tendency to structure objects and situations around them into schema, well-organized systems. The older people become, the more confidence and experiences they establish into their structures. Ideally, the more consistent an experience is within a structure, the more confidence an individual will place on that experience. As a result, when an individual encounters facts or tendencies that disrupt the structure, they will largely ignore it. What is deemed impure are objects or phenomena that do not correspond with the pre-existing social or symbolic structure. Douglas associates dirt as a form of disruption to order, therefore it must be excluded in order to maintain the integrity of the system. The Abomination of Leviticus Mary Douglas is also known for her interpretation of the book of Leviticus, in the Chapter The Abomination of Leviticus in Purity and Danger, in which she analyses the dietary laws of Leviticus II through a structuralist and symbolist point of view, and for her role in creating the Cultural Theory of risk. In The Abomination of Leviticus she states that the dietary laws were not based on medical materialism, but rather social boundaries, deeming that what is pure and impure is a way for a society to structure human experiences. At heart, what matters is using themes such as purity, separation and defilement to bring about order and structure to unorganized experiences. In Leviticus II, when categorizing which animals are authorized to be consumed, the pig is prohibited because while it has cloven feet like cows or goats, it does not produce milk, making it an anomaly within the structure of the world, hence its exclusion from the structure and its categorization as an impure animal. Natural Symbols (1970) In Natural Symbols (first published 1970), Douglas introduced the interrelated concepts of "group" (how clearly