The Eucharist: the Body's self-sustenance

The second reading today, about the Church as the body of Christ, sent my mind wandering a bit, and it occurred to me that we can infer from this an interesting explanation of the Real Presence. Someone has probably said this before—it wouldn't surprise me if my subconscious was dredging up something I've read long ago—I just hope that, if so, I'm dredging up something correct, and not marring it by my choice of words.

All of us are members of the Body of Christ, in the corporal sense of the word "member": each with his or her role. Just as the members of a body need nourishment, so do the members of the Body of Christ.

Unlike a human body, the Body of Christ does not need external nourishment, but is nourished by its communion with the Head, Christ our Lord. For example, when someone fasts completely from food, the body takes no nourishment outside itself, but converts fat into nourishment: it is internal to the body, but external to each member that is nourished. Likewise is the Eucharist not external to the Body of Christ, but from itself. That said, the analogy goes only so far: a human body loses part of itself by the conversion of fat into nourishment, whereas the Body of Christ converts nothing; rather, Christ, our Head, draws our nourishment from the inexhaustible fountain of divine grace.

So this communion, which we receive in the Eucharist, is a communion with the real, glorified Body and Blood of Christ. As occurs with the nourishment of a human body, each member receives something external to oneself, for none of us is a source of grace; Christ alone is. However, we do not receive a different Body of Christ, as if there could be such a thing, let alone do we receive grace that is external to the Body of Christ: we receive grace from the Body itself, which by union with the divinity is self-sufficient. So people who see the Eucharist as a kind of physical or spiritual cannibalism are quite mistaken: a cannibal receives something external to oneself, but when the Body of Christ receives the Eucharist, it receives itself, not something external to it—external to the members, but not to the Body.

I am not really competent to explain it much further, if even this far, so I'll stop here.