"It is th[e] Magisterium's task . . . to guarantee [God's people] the objective possibility of professing the true faith without error."
"Ipse eum a deviationibus protegere debet et defectibus, eique possibilitatem obiectivam tutari fidem authenticam sine errore profitendi."
CCC 890, italics mine. Yet in CCC 889, it already says that "By a 'supernatural sense of faith' the People of God, under the guidance of the Church's living Magisterium, 'unfailingly adheres to this faith'" in fact ("«Mediante supernaturali sensu fidei», populus Dei « fidei indefectibiliter adhaeret», sub ductu vivi Magisterii Ecclesiae"). So the Magisterium provides a possibilitas that is then, of course, indefectibiliter realized in fact? The possibilitas must then be an objective grace, and the "'supernatural sense of faith'" that ensures the requisite adherence (given to the Body of Christ, but not to every individual), its subjective counterpart.