VATICAN CITY (RNS) — Pope Leo XIV named St. John Henry Newman a doctor of the church on Thursday (July 31), recognizing the lasting impact the 19th-century convert’s writings on conscience and the development of doctrine have had on the Catholic Church.

Newman was an influential figure in England’s Oxford Movement, which aimed to restore the Church of England to its Catholic roots. He converted to Catholicism in 1845 and was ordained a priest. The pope’s namesake, Leo XIII, made Newman a cardinal in 1879, even though Newman wasn’t a bishop.

The decision to enshrine Newman, who died in 1890, among the now 38 doctors of the church, including St. Augustine and St. Thomas Aquinas, was discussed during a plenary session of cardinals, bishops and members of the Vatican department for sainthood causes. Newman will be the second doctor of the church from England, after the Middle Ages monk St. Bede, who was recognized by Pope Leo XIII in 1899.

Among Newman’s most influential theological works was “An Essay on the Development of Christian Doctrine,” written in 1845, which argued that the application of Catholic doctrine may change over time even if its core truths stay the same. His reflections influenced the Second Vatican Council from 1962 to 1965, which sought to reconcile the church with modern society by promoting the role of laypeople, fostering interreligious dialogue and ecumenism, and making the liturgy more approachable for believers.

Pope Francis made Newman a saint in 2019, describing his sermons as examples for Catholics to be “kindly lights amid the encircling gloom.” The late pope spoke consistently about the development of doctrine, which he described not “as a static monolith” but as something that “grows, as a tree that remains the same but still flourishes and bears fruit,” in a 2019 speech to the International Theological Commission. He often cited the fifth-century monk St. Vincent of Lerins, who also wrote guidelines on how doctrine developed over time.

Newman’s works reflected on the importance of individual conscience, which he described as “the aboriginal Vicar of Christ” inside every person. He promoted ecumenical dialogue, urging conversations between Catholics and Anglicans, and evangelization based on kindness and respect instead of proselytism and judgment.

Additionally, Newman outlined principles to inspire Catholic liberal education, founding the Oratory School in Birmingham, England, and the Catholic University of Ireland, of which he was also a rector.

With Newman’s recognition as a doctor of the church, the Vatican affirmed it recognizes his influence beyond England in the larger church. It also seems to underscore Leo’s appreciation for his teachings, which were once considered controversial but are now a cornerstone of Catholic theology.

The Vatican has not yet announced when the official ceremony recognizing him as a doctor of the church will occur.