Catholic ecumenical councils in the context of "Ecumenical"

Sola scriptura (Latin for 'by scripture alone') is a Christian theological doctrine held by most Protestant Christian denominations, in particular the Lutheran and Reformed traditions, that posits the Bible as the sole infallible source of authority for Christian faith and practice. Sola scriptura is a formal principle of many Protestant Christian denominations, and one of the five solae theorized in the early 20th Century in attempts to characterize common ground in disparate Protestant theologies.

The Catholic Church considers it heresy and generally the Orthodox churches consider it to be contrary to the phronema of the Church. While the scriptures' meaning is mediated through many kinds of subordinate authority—such as the ordinary teaching offices of a church, the ecumenical creeds, councils of the Catholic Church, or even personal special revelation—sola scriptura in contrast rejects any infallible authority other than the Bible.

The Second Ecumenical Council of the Vatican, commonly known as the Second Vatican Council or Vatican II, was the 21st and most recent ecumenical council of the Catholic Church. The council met each autumn from 1962 to 1965 in St. Peter's Basilica in Vatican City for sessions of 8 and 12 weeks.

Pope John XXIII convened the council because he felt the Church needed "updating" (Italian: aggiornamento). He believed that to better connect with people in an increasingly secularized world, some of the Church's practices needed to be improved and presented in a more understandable and relevant way.

The Council of Trent (Latin: Concilium Tridentinum), held between 1545 and 1563 in Trent (or Trento), now in northern Italy, was the 19th ecumenical council of the Roman Catholic Church. Prompted by the Protestant Reformation at the time, it has been described as the "most impressive embodiment of the ideals of the Counter-Reformation." It was the last time a Catholic ecumenical council was organized outside the city of Rome, and the second time a council was convened in the territory of the Holy Roman Empire (the first being the Council of Constance).

The Council issued key statements and clarifications of the Church's doctrine and teachings, including scripture, the biblical canon, sacred tradition, original sin, justification, salvation, the sacraments, the Mass, and the veneration of saints and also issued condemnations of what it defined to be heresies committed by proponents of Protestantism. The consequences of the council were also significant with regard to the Church's liturgy and censorship.