The first quotation comes from the great American liturgical theologian Aidan Kavanagh's The Shape of Baptism (1978):
To know Christ sacramentally only in terms of bread and wine is to know him only partially, in the dining room as host and guest. It is a valid enough knowledge, but its ultimate weakness when isolated is that it is perhaps too civil....However elegant the knowledge of the dining room may be, it begins in the soil, in the barnyard, in the slaughterhouse; amid the quiet violence of the garden, strangled cries, and fat spitting in the pan. Table manners depend on something's having been grabbed by the throat. A knowledge that ignores these dark and murderous human gestes is losing its grip on the human condition.
Aside from the jarring juxtaposition of imagery so characteristic of Kavanagh's prose, there is an obvious inference he means for his readers to draw: to celebrate the Eucharist in the comfort and security of our often sanitized liturgies apart from an active remembrance of the suffering and sacrificial death of Christ is to ignore the abiding heart of the Eucharist: "Table manners depend on something's having been grabbed by the throat." In the decades following the Second Vatican Council, this concern to re/connect liturgy to life, worship to the witness for social justice, finds some of its profoundest articulations in theologians influential to, associated with and/or inspired by developments in Liberation Theology. Thinkers like Karl Rahner, Gustavo Gutierrez, Juan Segundo, Tissa Balasuriya, J. B. Metz, Edward Schillebeeckx, Piet Schoonenberg, and others have exceptional meditations on this aspect of the Eucharist, often tied to equally penetrating analyses of the sacramental presence of Christ.
For appreciating these points within an American context, I can't recommend anything more highly than the late Monika Hellwig's (1929-2005) still moving essay, The Eucharist and the Hunger of the World. Hellwig begins with a phenomenological description of the human experience of hunger (for food, freedom, meaning, truth, authenticity, etc) along with a description of the basic Eucharistic action as the sharing of a meal, and then employs these to underscore and reinforce a belief in the radical interdependency of all people. Through a series of compassionate sketches of how global poverty stalks and brutalizes its victims, leaving them bereft of not only sustenance but even human dignity itself, Hellwig concretizes the meaning of the Eucharist for a needy world.
This leads me to my second, and significantly longer, quotation from Sara Miles's memoir Take This Bread. It's a curious book, as its author confesses, since it charts the most unlikely of conversions. But for that very reason, an eminently appropriate religious book. The following passage comes from the prologue, pp. xiii-xv:
Beyond any single moment of epiphany, my conversion was a long, complicated, and often unconscious journey. When I left the home of my atheist parents, I had no reason to think I was looking for God: I just knew I wanted to experience meaning and connection. The material world was my ground: bodily experiences the context in which I searched for knowledge and love, political and moral purpose. I looked in all kinds of places, often extreme: in the heat and exertion of restaurant kitchens, in poor people's revolutions and in war zones, in engaged journalism and passionate politics, in love affairs with men and women, in the birth of my child. Something was tugging at me. It drew me form individual experience to collective experience, crossing lines each time -- lines of family, of nation, of people, unlike me -- to find intimate human connection. I saw people betray their friends sacrifice for strangers; I saw people suffer and starve; I saw people transcend their own limitations to nurture others and become part of communities. Everywhere I saw bodies and food.
Food and bodies had always been wrapped in meaning for me: They were my way of understanding the world. But it would take decades to have these accumulated experiences make sense in a narrative, much less one I'd call Christian. It took actually eating a piece of bread -- a simple chunk of wheat and yeast and water -- to pull those layers of meaning together: to make food both absolutely itself and a sign pointing to something bigger. It turned out that the prerequisite for conversion wasn't knowing how to behave in a church or having a religious vocabulary or even a priori "belief" in an abstract set of propositions: It was hunger, the same hunger I'd always carried.
Holy communion knocked me upside down and forced me to deal with the impossible reality of God. Then, as conversion continued, relentlessly challenging my assumptions about religion and politics and meaning, God forced me to deal with all kinds of other people. In large ways and small, I wrestled with Christianity: its grand promises and its petty demands, its temptations and hypocrisies, its ugly history and often insufferable adherents. Faith for me didn't provide a set of easy answers or certainties: It raised more questions than I was ever comfortable with. The bits of my past -- family, work, war, love -- came apart as I stumbled into church, then reassembled, through the works communion inspired me to do, into a new life centered on feeding strangers: food and bodies, transformed. I wound up not in what church people like to call 'a community of believers' -- which tends to be code for 'a like-minded club -- but in something huger and wilder than I had ever expected: the suffering, fractious, and unbounded body of Christ.
The Eucharist becomes, to slightly re-purpose the phrasing of the medievalist and theologian Oliver Davies, "the thematic key not only to the way the world is, but also to what and how we are, and to what God has given us of himself to hold and to understand" (The Creativity of God: World, Eucharist, Reason, p. 7). This is all a case of what Davies would further term "eucharistic semiotics." It was and remains a goal of the Second Vatican Council that our liturgical signs should, rather than be kept safe in highly ritualized observes, really signify. To appreciate the Eucharist has the summit from and toward which everything flows is to risk disturbing our worship habits. Truly there is no more "perverse core" to Christianity (to borrow Zizek's phrase) than what Sara Miles's conversion taught her to understand: the material world is our ground, but it is a world of "food and bodies, transformed."