Summary — In conclusion to the preceding researches on the title « Patriarch of the West», the Author proposes some doctrinal considerations, examining in the light of Vatican II whether the pentarchic theory and the coexistence of primatial and patriarchal powers in the same person of the Bishop of Rome are reconcilable with the supreme authority of the Roman Pontiff. As to the first aspect, he maintains that, since the patriarchal powers are a participation of the supreme authority of the Pope, one can speak of patriarchal powers with reference to the Eastern patriarchs. The pentarchy, however, understood as a collective responsibility of the patriarchs within the universal Church, is not reconcilable with the doctrine of the primacy. As to the second aspect, the Author holds that one cannot conceive in the Pope an intermediary « super-episcopal » or patriarchal power, which would confer on him specific powers on the West, distinct from those deriving from the primacy. The title « Patriarch of the West» seems, therefore, to be without any doctrinal foundation. In the end, the Author, relying on Vatican II, considers as somehow inopportune the constitution of patriarchs in the West also, especially when one considers that the episcopal Conferences constitute more adequate modalities of a partial exercise of the collegiality.