Extraordinary Magisterum
...the Holy Spirit was promised to the successors of Peter not so that they might, by his revelation, make known some new doctrine, but that, by his assistance, they might religiously guard and faithfully expound the revelation or deposit of faith transmitted by the apostles.
(Vatican I, Chapter 4, Section 6.)
Ordinary Magisterum
The Ordinary Magisterum consists of the day-to-day, non-infallible, yet authoritative teaching of the Pope and bishops (e.g., encyclicals, pastoral letters) regarding faith and morals. It requires "religious submission of mind and will," distinct from the "assent of faith" given to infallible teachings [Canon 752].
Key Standards and Criteria:
Consistency and Universality: The teaching must align with the constant and universal tradition of the Church.
Content Focus: It deals with faith and morals.
Source: It is exercised by the Pope in his ordinary capacity or by bishops in their everyday teaching role.
The Catholic Church does not define a specific number of years (like "100 years" or "three centuries") to satisfy the requirement of continuity. Instead, the focus is on a teaching being held "always and everywhere" (semper et ubique) across the history of the Church.
The standard for continuity involves several factors:
Dating Back to the Apostles: For a doctrine to be part of the Ordinary and Universal Magisterium, it must generally be traceable back to the Apostolic Deposit of Faith. It is often described as a "consistent teaching of the Church for millennia".
The Vincentian Canon: Theologians frequently apply the "Vincentian Canon" (from St. Vincent of Lérins): that which has been believed everywhere, always, and by all.
Diachronic Universality: This means universality not just across space (all bishops around the world today) but also across time (bishops throughout different centuries).
Manifestly Evident: According to Canon Law, no doctrine is understood as being infallibly defined unless it is "manifestly evident". If a teaching has fluctuated or changed significantly over time, it likely does not meet the "manifestly evident" standard of continuity required for infallibility.
In practice, this means if a teaching has been consistently proposed as a definitive truth from the early Church through the medieval period and into the modern era, it fulfills the continuity requirement.