individual body can change its qualities and constituency by having other external parts, such as another body, added to it: when the two bodies are connected, they conceptually form (at least in terms of impurity) one shared body, and when they are no longer connected, each of the bodies functions as a separate unit.
In this regard, the human body is no different from other modular inanimate objects to and from which parts can be added or removed. The rabbis refer to such parts that can be removed or added as hibburim, “appendages,” a term they use to discuss things that are detachable from a specific artifact and yet when connected to it function as one unit with it (for example, the drawers of a chest or the handle of a pan). When the “appendage” is connected to the item in question, they form one unit for the purpose of contraction and conveyance of impurity: if the appendage becomes impure, then all of the object will become impure, and if the object becomes impure, the appendage will also become impure. The rabbis of the Mishnah dedicate lengthy discussions to sorting the different components of various artifacts in order to figure out whether and which of these components are “appendages,”39 and they similarly use this term when discussing different components of particular foodstuffs.40 Thus, the same principle that we have seen in regard to bodily contact between persons also pertains to the transmission of impurity from one artifact to another, for example:
If a bed was impure on account of treading (teme’a midras, that is, an impure person stepped or leaned on it), and one appended a mattress to it, all of it (that is, the bed and the mattress) is impure on account of treading. Once [the mattress] was separated, [the bed] is impure on account of treading, and the mattress is impure on account of touching [that which is impure on account of] treading (maga midras).41
The same mechanism of impurity-sharing, then, is evident both in the case of human bodies and in the case of inanimate objects: as long as the two components are “appended,” they function as a single unit in terms of impurity, and they both share the impurity status of the source. Once the physical connection is undone, the “appendage”—whether a person or object—is only residually impure, in such a way that the impurity degree of the person or object is once-removed from that of the source.
The rabbinic view of the human body as a modular mechanism, from and to which things can be removed or added, is evident not only in the notion that two bodies can be “connected” so as to constitute, in terms of impurity, one body, but also in the rabbinic consideration of several bodily components within a single body as “appendages.” This term is used, in the context of human bodies, to refer to hair, nails, and teeth, three bodily constituents with which one is not born and that are disposable throughout one’s life, in such a way that their pertinence to the body is seen as secondary. These three components partake in the impurity of the body as long as they are connected to it, but are no longer impure once they are separate from it: for example, the teeth, hair, and nails of a corpse convey corpse impurity as long as they are connected to the corpse, but not once they are set apart from it.42 Accordingly, we find in the Mishnah statements such as this one:
If the appendages of the impure [person] were on the pure [person], or if the appendages of the pure [person] were on the impure [person]—[the pure person] is impure.43
This passage concerns carriage as one of the modes in which impurity is conveyed by persons with genital discharges: as a rule, persons with genital discharges convey impurity to everyone that they carry and to everyone that carries them. The question at hand is what happens if the body parts that are being carried are parts that are considered to be “appendages” of the body. Since they do not fully belong to the body, can they be said not to convey or contract impurity in this situation? While the Mishnah does not explain what it means by “appendages,” it is reasonable to understand this passage in light of the Tosefta, which specifies that the discussion relates to teeth, hair, and nails.44 We see, then, that the human body is not a fixed, unified, and monolithic entity: it is seen as consisting of various parts, and its different constituents are subject to different rules when it comes to the contraction and conveyance of impurity.
This perceived modularity of the human body is what enables, I suggest, one of the most perplexing rabbinic (or protorabbinic) innovations, namely, the ruling that one’s hands are constantly impure (in a low degree) regardless of the impurity status of the person as a whole. One’s entire body can be certifiably pure, but unless one has just washed one’s hands this very instant, his hands are considered to be “second to impurity” in such a way that they disqualify a heave-offering just by touching it, and if one’s hands are wet, they also transmit impurity to ordinary food.45 The reason for this constant status of impurity, as stated in the Mishnah, is that the hands always “busy themselves” (she-ha-yadayim ‘asqaniyot), that is, one’s hands are likely to do things and touch things of which their “owner” is not aware.46 In other words, the rabbis assume a certain dissociation of the hands from the rest of the body insofar as the hands have “a will of their own,” and therefore ascribe to the hands an impurity status that is independent of the rest of the body. This partial dissociation between hands and body brings to the fore situations such as the following:
If one was eating fig-cake with unwashed hands (yadayim mus’avot) and he put his hand inside his mouth to remove the waste, R. Meir renders [the fig-cake] pure, and R. Yehuda renders it impure.47
The case here is of a person who is overall pure, but his hands are unwashed and thus impure in a low degree. As long as his hands are dry, they do not transmit impurity to the fig-cake he is eating, since his hands’ impurity is too minor to impact it, but once he moistens his hand, his saliva transmits impurity from the hand to the fig-cake and renders the fig-cake itself impure (as we may recall, liquids function as duplicators of impurity). Thereby, once the person ingests the impure fig-cake, he himself becomes impure. The controversy between R. Meir and R. Yehuda seems to pertain to the question of whether one’s saliva can indeed function as such “duplicating” liquid when it is still in one’s mouth, but for our purposes the striking notion here is that a person’s own hands can serve as “external” entities which can, through the mediation of liquids and foods, make the very same body to which they are attached impure. While I cannot get into the very complex and contested history and development of the notion of the impurity of hands here,48 I do wish to point out that the rabbis could not have ascribed an independent impurity status to hands had they not held a broader perception of the human body as a modular mechanism, that is, as an entity with different constituent parts that, while operating together as one, also have independent existence. Of course, the rabbis did not consider one’s hands to be “appendages” of the body in the same manner as hair and nails, but they did consider the body to be a divisible entity, which can be parsed and subclassified by drawing distinctions between the parts of which it consists.
The status of one’s saliva, which I mentioned in passing above, is an even more radical case in point for the modularity of the rabbinic body of impurity. The rabbis maintain that one’s saliva is part of the body as long as it is “attached” to one’s mouth, and thereby it partakes in whatever the body’s impurity status may be. However, once saliva is detached (that is, extracted from the palate), even if it is still contained in the mouth, it becomes separate from the body and functions as an independent entity. The following passage demonstrates this view:
If a menstruating woman put coins in her mouth and went down and immersed, she is pure of her [menstrual] impurity, but impure on account of her saliva.49
The admittedly bizarre case described here is of a woman who is going to immerse for purification at the end of her menstrual period. Before she immerses, she puts coins in her mouth for whatever reason (perhaps she is afraid they will be stolen?), as a result of which saliva is detached from her palate and is attached to the coins. Now this woman is in an odd state: her body is overall pure, due to the immersion, but in her mouth there is saliva that was detached from her palate while she was still impure (that is, before the immersion). In other words,
