Dear Clemens Maria, you asked what was Fr. Fenton's view, I think it might interest you to know that he believed, as many theologians still did right up until Vatican II, that explicitly believing in Jesus Christ by divine and Catholic Faith, and loving Him with divine charity or contrition, was necessary for salvation.
In the American Ecclesiastical Review, in Dec. 1952, this eminent theologian wrote, "most theologians teach that the minimum explicit content of supernatural and salvific faith includes, not only the truths of God’s existence and of His action as the Rewarder of good and the Punisher of evil, but also the mysteries of the Blessed Trinity and the Incarnation." These two doctrines are the core mysteries of the Catholic Faith, as the Athanasian Creed for example attests, and St. Thomas with almost all the Doctors like St. Robert, St. Bernard, St. Alphonsus etc held. Based on Magisterial texts of St. Pius X, of Clement XI, and of Alexander VII, as well as the consent of the Fathers, many theologians used to argue that this Papal teaching was irreformable, even though the Church does not censure the contrary proposition. This teaching, at any rate, was almost completely disregarded in the aftermath of the Council.
Fr. Wathen was in many ways a good priest during a period of immense difficulties in the Church, but, as per what has been posted above, he clearly fell into error on this point. He is not in agreement with the traditional teaching of the Church, which cannot be mistaken, therefore on this point, his opinion must be rejected. It is not correct to say or to think that those who hold the doctrines of Baptism of Desire are Blood are "at least material heretics." They are nothing of the sort. Fr. Wathen should rather have made the traditional teaching of the Church, in that immutable sense in which they have always and everywhere been understood, "the basis for" his own otherwise commendable "labors" to "seek to maintain and restore traditional Catholicity."
Anyway, I will post some sources on this in another thread, perhaps with a text in the library section. It doesn't belong in this thread.