Most of us, Catholic or not, must be concerned by the Pope’s illness and increasing infirmity. Is there any rule or tradition of the Church that prevents him retiring? As far as I know, cardinals, bishops and priests all are permitted (or even obliged) to retire.
Yes, a pope may retire if he chooses to do so, something provided for in canon law (cf. canon 332 §2, Code of Canon Law, 1983). However, unlike cardinals, bishops, or priests, a pope can never be required to retire. This is because he “has supreme, full, immediate and universal ordinary power in the Church, and he can always freely exercise this power” (canon 331), and, because of such power, does not answer to another ecclesial authority who can require his retirement.