The Roman Catholic and the Orthodox Churches, as well as other Christian communities, are faced with the challenges of postmodern thought, which calls into question some of the foundational theological and philosophical constructs through which Christianity has articulated the mystery of Eucharistic presence. Louis-Marie Chauvet, Alexander Schmemann and John Zizioulas, the interlocutors presented in this dissertation, recognize that for centuries, Eucharistic theology has been shaped within a metaphysical/Scholastic framework which confines, in many respects, the experiential/relational aspects of the divine/human dynamic as mediated in the Eucharistic celebration. An appeal for a paradigmatic shift is made evident in their respective works based on a renewed understanding of the various strata of the symbolic order and the paradigm of relationality as being the primary contexts within which the people of God celebrate his presence. This shift is necessary in order to correct the problematic of a causal, mechanistic, reductionist, overly-metaphysical, dualist framework as well as a static onto-theological construct, to which Eucharistic theology has been subjected to for centuries. There is a call for a re-thinking of Eucharistic presence in light of a theology which is rooted in the mutually supportive principles of lex orandi est lex credendi and of a Patristic theological landscape. The methodology of this dissertation is comparative and dialogical in nature in which each theologian articulates the need for a scholarship of Eucharistic presence to be established on new terrain and a new trajectory which will prove to be more appropriate in expressing the mystery of presence as it is grounded and expressed within the Apostolic faith and practice.<br>By appealing to and implementing the theologies here presented, we can develop a renewed vision of Eucharistic presence that may provide a common ground for an ecumenical enterprise, reaffirming the most essential component of faith: God's presence among humanity and in creation. This ecumenical enterprise must not remain within the realm of the abstract or theoretical, but needs to culminate in a true union of the churches born of a common unity in faith and eventual Eucharistic practice. In addition, these three theologians' contributions will continue to provide contemporary and future scholars in sacramental theology with an innovative approach to further articulate the mystery of presence through media which speak to the contemporary world while remaining rooted in antiquity. / McAnulty College and Graduate School of Liberal Arts; / Theology; / PhD; / Dissertation;