8 These two events—the one full of sorrow, the other full of joy—attest clearly to the world that while all things human gradually decline and decay, the Roman Pontificate withstands the rush of centuries, even though the visible Heads of the Church must, one after another, leave this mortal exile as they complete the span of days which God in His providence has set for them.
Source: Grata Recordatio (Vatican.va)