Unitatis

Unitatis is the genitive singular form of the Latin noun Unitās, meaning unity or oneness. In Latin grammar, Unitās is a feminine noun of the third declension; its genitive singular is Unitatis. The term appears in various Latin phrases and titles, including ecclesiastical usages such as Unitatis redintegratio.

Unitatis redintegratio is a Vatican II decree on ecumenism and the restoration of Christian unity. Promulgated in the 1960s, it addresses the Catholic Church’s relations with other Christian communities and the broader ecumenical task. The document emphasizes dialogue and collaboration with non-Catholic Christians, acknowledges that elements of truth and sanctification can be found outside the Catholic Church, and advocates a respectful, non-proselytizing approach. It discusses the baptism of believers as a common basis for unity and calls for shared witness to the Gospel, while affirming the Catholic Church’s regard as the Church of Christ. The decree has been influential in shaping modern Catholic ecumenical practice and inter-Christian relations.

Beyond that specific use, Unitatis typically appears in Latin writings to express the concept of unity or oneness and can appear in various phrases, titles, or doctrinal formulations in religious and secular contexts.