What was the Second Vatican Council, and what did it change?

The Second Vatican Council, usually called Vatican II, was the twenty-first ecumenical council of the Catholic Church. It met from 1962 to 1965 to present the perennial faith more effectively and renew the Church's pastoral life and mission.

What happened at the council. Pope St. John XXIII convoked Vatican II, and Pope St. Paul VI continued and concluded it. More than two thousand bishops participated. The council produced sixteen documents, including four major constitutions: Sacrosanctum Concilium on the liturgy, Lumen Gentium on the Church, Dei Verbum on divine revelation, and Gaudium et Spes on the Church in the modern world.

What it taught. Vatican II emphasized the universal call to holiness, the role of the laity, episcopal collegiality under the pope, active participation in the liturgy, deeper use of Scripture, ecumenism, missionary work, and the dignity of the human person. It taught that Scripture and Tradition together transmit the one deposit of God's Word, authentically interpreted by the Church's Magisterium (CCC 80-82, 95). It also encouraged Catholics to work for Christian unity while preserving the truth that the fullness of the means of salvation subsists in the Catholic Church (CCC 816, 820-822).

What changed afterward. The council authorized a reform of the Roman liturgy and permitted wider use of vernacular languages, while stating that Latin was to be preserved in the Latin rites. Later popes implemented the reform through revised liturgical books. Other disciplinary and pastoral changes included restored emphasis on the permanent diaconate, expanded lay participation, revised catechetical methods, and stronger dialogue with other Christians and non-Christian religions.

Vatican II also taught religious freedom as immunity from coercion in civil society. No one should be forced to act against conscience in religious matters, within just limits. This does not mean that all religions are equally true or that conscience creates moral truth (CCC 2104-2109). Christ remains the one Savior of mankind (Jn 14:6; Acts 4:12).

What it did not change. Vatican II did not abolish Latin, reject Tradition, replace the Mass with a community meal, or revise doctrines such as the Trinity, the Real Presence, original sin, priestly ordination, or the moral law. Dogma cannot be reversed. Doctrinal expression can develop, and disciplines can be reformed, but the apostolic faith remains the same.

Read the council's documents through the Church's living Tradition and later papal teaching. Distinguish what Vatican II actually said from experiments, misunderstandings, and abuses that followed it.