"…De Fide means “of the faith”. It means it is an article of faith and must be believed. A Dogma is a De Fide article of faith. In Catholicism, there exists what we understand to be a “hierarchy of truths”. Some doctrines have been formally defined by the Church (i.e. dogmas) and are essentially irrevocable and non-reformable. Other doctrines do not carry such a weight but are generally believed to be true by the majority of theologians.
In his book The Fundamentals of Catholic Dogma, Ludwig Ott distinguishes between the level of certainty a Catholic may have towards any teaching of the Catholic Church (p.9-10). I have provided an example of each immediately following his description:
De Fide - The highest degree of certainty appertains to immediately revealed truths, due on the Authority of God revealing. If these truths are solemnly defined by the Magisterium, they are “de defide definita”. (Example: The Dogma of the Trinity)
Fides Ecclesiastica - Catholic truths or Church doctrines, on which the infallible Teaching Authority of the Church has finally decided, are to be accepted with a faith which is based on the sole authority of the Church (fides ecclesiatica). These truths are as infallibly certain as dogmas proper. (Example: Anglican Order are invalid.)
Sententia Ad Fidem Pertinens - A teaching pertaining to the Faith is a doctrine, on which the Teaching Authority of the Church has not yet finally pronounced, but whose truth is guaranteed by its intrinsic connection with the doctrine of revelation (theological conclusions). (Example: An all male priesthood. Some may disagree and suggest that Ordinatio Sacerdotalis is an infallible pronouncement on this issue.)
Sententia Fidei Proxima - A teaching proximate to Faith is a doctrine, which is regarded by theologians generally as a truth of Revelation, but which has not yet been finally promulgated as such by the Church. (Example: Mary as Co-Mediaterix)
Sententia Communis - Common teaching is doctrine, which in itself belongs to the field of free opinions, but which is accepted by theologians generally. (Example: Christ’s soul possessed infused knowledge.)
Sententia Probabablis - Theological opinions of lesser grades of certainty are called probable, more probable, well-founded. Those which are regarded as being in a agreement with the consciousness of Faith of the Church are called pious opinions (sententia pia). The least degree of certainity is possessed by the tolerated opinion (opinio tolerata), which is only weakly founded, but which is tolerated by the Church. (Example: Rigorist (strict) view of “No Salvation Outside the Church”, or the existence of Limbo.)…"
Thanks to John Pacheco
The Catholic Legate
June 7, 2002