The Primacy of the Pope was not understood, therefore, in the administrative sense, but was wholly derived from a eucharistic ecclesiology." (Joseph Ratzinger, "Il Concetto della Chiesa nel Pensiero Patristico," in I Grandi Temi del Concilio, Rome: Paoline, 1965, pp. 154-155)
Regarding the immediate discussion in this thread about the about the *current authority* of the pope the above quotation is completely out of context.
It is important to underscore that then Cardinal Ratzinger, in the immediate context of the above remarks, was speaking of primacy as it had previously existed in the first Christian millennium.
It was not a statement about what primacy is like in the Roman Catholic Church today.
Then Cardinal Ratzinger fully acknowledges the obvious fact that primacy has undergone extensive further development in the Roman Catholic tradition beyond primacy as it existed in the first millennium situation described in M's quotation
(cf. Ratzinger, Principles of Catholic Theology
discusses this in some detail).
Then Cardinal Ratzinger's observations are certainly worthwhile per se, however they are not germane to the discussion which we have been having in this thread in the last couple of pages about the nature of papal authority in the Roman Catholic tradition today.
 In a discussion of Orthodox and Roman Catholic dialog then Cardinal Ratzinger writes: "How, then, are the maximum demands to be decided in advance? Certainly, no one who claims allegiance to Catholic theology can simply declare the doctrine of primacy null and void, especially not if he seeks to understand the objections and evaluates with an open mind the relative weight of what can be determined historically. Nor is it possible, on the other hand, for him to regard as the only possible form and, consequently, as binding on all Christians the form this primacy has taken in the nineteenth and twentieth centuries. The symbolic gestures of Pope Paul VI and, in particular, his kneeling before the representative of the Ecumenical Patriarch were an attempt to express precisely this and, by such signs, to point the way out of the historical impasse... Rome must not require more from the East with respect to the doctrine of primacy than had been formulated and was lived in the first millennium... Rome need not ask for more. Reunion could take place in this context if, on the one hand, the East would cease to oppose as heretical the developments that took place in the West in the second millennium and would accept the Catholic Church as legitimate and orthodox in the form she had acquired in the course of that development, while, on the other hand, the West would recognize the Church of the East as orthodox and legitimate in the form she has always had. (Cardinal Ratzinger, Principles of Catholic Theology
, pp. 199-200).