Paul Tillich, A History Of Christian Thought
Augustine. Donatism. The Medieval Church. Scholasticism. Mysticism.
There was one point remaining to be discussed in Augustine, namely his doctrine of the Church, and since this is of extreme influence in all the Christian churches – not only the Roman – we must deal with it. I gave you the basic ideas of Cyprian’s doctrine of the Church, namely that the Church is an institution of salvation; the concept of the communion of the saints (communio sanctorum) was largely replaced by that of the institute of salvation, in Cyprian and the whole development of which he is the representative, the institution of salvation being an objective thing, in which we participate.
In this situation Augustine came into conf lict with the Donatist movement. The consequence of the institution meant a change in the idea of the holiness of the Church (una ecclesia sancta .). These ideas meant something other than what they meant originally. Originally the emphasis was on the sanctification of the individual members and the group as a whole. Now this emphasis is changed to the sacramental reality of the Church, the holiness of the Church is identical with the sacramental gifts, especially with the sacramental power of the clergy. Sanctus, holy, saint, does not mean now, any more, someone who is personally sanctified, but it does mean someone who has the sacramental power. This of course is a fundamental change in meaning, from the subjective to the objective element, from personal holiness to institutional holiness.
There were people in North Africa, where Augustine was bishop, who didn’t want to follow this development and who were interested in the actual sanctification of the Church and its members, especially of the clergy. The points in which this problem arose were the following: 1) the discipline in the act of penitence; 2) the question whether baptism is valid if performed by heretics; 3) the question whether ordination is a possible thing if it is done by traditores , traitors, who in the persecutions delivered over the holy books, or denied they were Christians.