Fernando Belo’s summary of the symbolic system of purity (A Materialist Reading of the Gospel of Mark, 38-9) is a bit too schematic, but still illuminating.
He sees two overlapping systems in the Pentateuch: one of pollution/contagion and one of debt. I focus on the first. Israel’s “symbolic field was organized around three centers, each of which corresponds to one of the three instances of a social formation. All three were centers of foci of consumption: the table, the ‘house’ (in the sense of a group of kinspeople . . .), and the sanctuary; this means the consumption of food at meals, consumption of bodies in sexual activity, and ideological consumption in religious sacrifice.”
Each focal point was a center of purity “from which is excluded the impure, the misshapen, the undifferentiated, anything that breaks down forms.” Belo sees behind this an effort to keep life and death distinguished. “The consumption practiced at table, in sexual union, and in religious worship is a fusion, an eating that is sought as a goal of human life and a blessing; it involves two different but mutually compatible elements: humanity and its food, the bodies of man and woman, God and his people. These forms of consumption are life.”
Impurity or pollution is “confusion and the dissolution of the elements involved,” and thus constitutes a curse. “People reject it to the point of avoiding even simply contact or touching, since the impure is so violent as to be contagious. It brings death.”
The specifics of Levitical impurity fit pretty well into this scheme, but Belo, following Bataille, thinks that there’s also a dialectic here that works at cross-purposes with the simple binary of pure and polluted. Bataille points out that life and death are “not simply intrinsic” to each other. Rather, “death is at the very heart of life.” Belo explains, “If there is a permanent concern about food and the purity of the table, this is because all that humanity has to eat is corpses. If there is a permanent concern about sex, the reason is that sexual desire is a form of violence and deadly on two scores; It is deadly in itself; there we have Bataille’s essential thesis: he maintains that the taboos on incest, for example, are only specialized forms of a general, unformulated taboo relating to the danger inherent in sex. Sex is also deadly in the long run, inasmuch as the children who are the result of sexual activity ultimately take their parents’ place. Finally, if the blood of the victims, that is, something impure, is what serves to purify the altar and the offerers, the reason is that at the very heart of the blessing bestowed by God on the pure and just Israelite . . . the curse of death is at work against that same Israelite. Life . . . involves an immense, prodigal waste; everything dies to that life may go on in profusion” (43).
Rather than expose a fault line in the biblical purity system, though, this Bataillean analysis shows the limits of a simple homology between life/death and pure/polluted. The blood that purifies is not impure blood; only blood from the flesh defiles (Leviticus 15), and the only dead bodies that defile are those that die of themselves, not those that are killed (otherwise, the priest would be in a constant state of impurity). Death and life are connected to the purity system, but they aren’t exhaustively explanatory. Other factors are needed fully to explain the logic of the system.