Laudator Temporis Acti

Geoffrey Chaucer, "Clerk's Tale," Canterbury Tales IV.116-126 (tr. Nevill Coghill):

                                                   Invoke
Your wisdom, ponder carefully and see
How variously days pass; the seasons flee
Away in sleeping, waking, roaming, riding.
Time passes on and there is no abiding.
Still in the flower of your youth's delights
Age creeps upon you, silent as a stone.
Death menaces all ages and he smites
The high and low, the known and the unknown;
We see for certain, are obliged to own
That we must die, but we are ignorant all
Of when the hour's to come, the blow to fall.

And thenketh, lord, among youre thoghtes wise
How that oure dayes passe in sondry wise;
For thogh we slepe, or wake, or rome, or ride,
Ay fleeth the time; it nil no man abide.
And thogh youre grene youthe floure as yit,        120
In crepeth age alwey, as stille as stoon.
And deth manaceth every age, and smit
In ech estaat, for ther escapeth noon.
And also certein as we knowe echon
That we shul die, as uncertein we alle        125
Been of that day whan deth shal on us falle.

Petrarch, Epistolae Seniles XVII.3 (to Boccaccio), tr. Thomas Farrell in Sources and Analogues of the Canterbury Tales, edd. Robert M. Correale and Mary Hamel, Vol. I (Cambridge: D.S. Brewer, 2002), pp. 112-113:

The rapid days fly by, and even in the flower of your youth, silent and relentless age always stalks that flower: death is near at any age. No one is exempt from this duty; all must die. And while so much is certain, no one knows when death shall come.

Volant enim dies rapidi, et quamquam florida sis etate, continue tamen hunc florem tacite [senectus] ingreditur, morsque ipsa omni proxima est etati. Nulli muneris huius immunitas datur, eque omnibus moriendum est; utque id certum, sic est illud ambiguum quando eveniat.