In “Living Tradition,” No. 12 (July 1987), the present writer favourably reviewed a recent book by Fr. Ermenegildo Lio, O.F.M., “Humanae Vitae e Infallibilita” (Vatican City: Libreria Editrice Vaticana, 1986), in which the thesis is sustained that the teaching against contraception in Pope Paul VI’s encyclical letter “Humanae Vitae” (25 July 1968) is infallible, not merely by virtue of being an instance of the constant, ordinary and universal magisterium of the Popes and Catholic Bishops against this practice, but because the encyclical itself contains (in article 14) an “ex cathedra” definition. Lio claims, in other words, that “Humanae Vitae” contains an intrinsically infallible pronouncement: an instance of papal infallibility as defined by Vatican Council I.
To my knowledge Lio’s book has been virtually ignored by the theological community, in spite of his eminent qualifications as a professor of long standing in Rome’s Pontifical Lateran University, as a “peritus” at Vatican Council II, and an adviser to Pope Paul VI over the birth control issue–not to mention a personal autographed letter from Pope John Paul II thanking Fr. Lio for the presentation of his book, which was published by the Vatican Press.
Certainly, Lio’s thesis goes against the common view of theologians (both those who assent to “Humanae Vitae” and those who dissent from it), who have usually described the encyclical as being, in itself, a “non-infallible” document. Very often this conclusion seems to be drawn merely from the fact that there is no definition of a “dogma”–a point of “revealed” truth to be held as “of faith” (“de fide”)–in Pope Paul’s encyclical. But Lio’s point is that such definitions, while they represent the most solemn form of papal teaching, are not the “only” form which satisfies the conditions for an “ex cathedra” definition as laid down by the constitution “Pastor Aeternus” of Vatican I. In this paper I propose to develop this theme, in support of Lio’s thesis, i.e., the “ex cathedra” status of “Humanae Vitae.”
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