The life given us by nature is short; but the memory of a well-spent life is eternal.

[Brevis a natura nobis vita data est; at memoria bene reditae vitae sepiterna.]

Marcus Tullius Cicero (106-43 BC) Roman orator, statesman, philosopher

Philippics [Philippicae; Antonian Orations], No. 14, ch. 12 / sec. 32 (14.12/14.32) (43-04-21 BC) [ed. Hoyt (1896)]
    (Source)

Asking the Senate to honor the Fourth and Martian legions for their victory over Antony at the Battle of Forum Gallorum.

(Source (Latin)). Other translations:

Short is the life which nature has given us: but the memory of a life nobly laid down is eternal.
[ed. Harbottle (1897)]

A brief life has been allotted to us by nature; but the memory of a well-spent life is imperishable.
[tr. Yonge (1903)]

Brief is the life given us by nature; but the memory of life nobly resigned is everlasting.
[tr. Ker (Loeb) (1926)]