Francis A. Sullivan says that the one Church of Christ continues to exist perfectly in the Catholic Church, and is present imperfectly in other churches and ecclesial communities. However, he thinks Lumen Gentium 8 also enables us to say that the many churches, non-Catholic and Catholic, are all in the one Church of Christ, since to say the one Church of Christ subsists in the Catholic Church means no more than “continues to exist in” the Catholic Church. In this way, he denies the identity of the one Church of Christ and the Catholic Church. We point out that magisterial documents since Vatican II have consistently refused this proposal, and have instead spoken only of the one Church being present or operative, according to degrees, in non-Catholic churches and communities. We argue that while it is true there is “ecclesial reality” outside the Catholic Church, in that there are elements of truth and sanctification outside of her, the one Church of Christ of which Vatican II expressly speaks is the Church with all the gifts of unity and instruments for salvation with which Christ endowed it. The Catholic Church is not contained in any larger divinely willed and dominically instituted ecclesial reality, and it is without qualification the one Church of Christ and the one Church of Christ is without qualification the Catholic Church.