Objection 2: Vatican 1 taught that St. Peter has perpetual successors; therefore, long vacancies in the See of Peter are not possible.
Answer: Now where does the Church determine how long a vacancy may exist in the See of Peter. Between the death of Pope Clement IV (Nov 29,1268) and the election of Pope Gregory X (Sept 1, 1271), there was an interregnum of nearly three years. During the Western Schism, there were three claimants to the See of Peter; theologians teach that even if none of them were pope, that would not be against the promise of Christ or the teaching of perpetual successors.
Proof:
A. Institutiones Theologiae Fundamentalis [1929]
B. The Relations of the Church to Society [1882].
C. The Catholic’s Ready Answer [1915]
D. The Defense of the Catholic Church [1927]