Appearing on the front page of the Friday (April 23) edition of L'Osservatore Romano, the article responded to an April 16 open letter that Kung wrote to the world's Catholic bishops.
In that letter, the Swiss theologian accused Benedict of betraying the modernizing reforms of the Second Vatican Council (1962-65) and of engineering, when still known as Cardinal Joseph Ratzinger, a "worldwide system of covering up cases of sexual crimes committed by clerics."
Responding in L'Osservatore Romano, Pier Giordano Cabra (identified as Kung's first publisher in Italy) addressed the theologian in the form of a letter, under the headline "Dear Hans."
Cabra told Kung that "perhaps if your letter had breathed a bit more of the hymn to charity, it would have turned out to be a more elegantly evangelical gesture of congratulations" for Benedict's 83rd birthday and fifth anniversary as pope, as well as "a more fruitful contribution to the church that is suffering for the weakness of her sons."
Kung and Ratzinger were colleagues on the theology faculty of the University of Tubingen, Germany, in the mid-1960s. The two have long been opponents in theological debates.
Pope John Paul II deprived Kung of his license to teach as a Catholic theologian in 1979.
A stronger response to Kung came on Wednesday (April 21) from George Weigel, the American biographer of John Paul II.
Writing on the Web site of the magazine First Things, Weigel condemned Kung's letter as a "piece of vitriol ... utterly unbecoming a priest, an intellectual, or a gentleman," above all for its charge that Benedict engineered a cover-up of clerical sex abuse.