The great and glorious masterpiece of man is to know how to live to purpose; all other things, to reign, to lay up treasure, to build, are, at most, but little appendices and props.

[Le glorieux chef-d’oeuvre de l’homme, c’est vivre à propos. Toutes autres choses ; regner, thesauriser, bastir, n’en sont qu’appendicules et adminicules, pour le plus.]

Michel de Montaigne (1533-1592) French essayist

Essays, Book 3, ch. 13 “On Experience [De l’Experience]” (after 1588) (3.13) (1595) [tr. Cotton/Hazlitt (1877)]
    (Source)

This passage was added to the original version of the essay, published 1588, for the 1595 edition.

(Source (French)). Alternate translations:

The glorious master-piece of man, is, to live to the purpose. All other things, as to raigne, to governe, to hoarde up treasure, to thrive and to build, are for the most part but appendixes and supportes thereunto.
[tr. Florio (1603)]

The glorious Master-piece of Man is to know how to live to purpose; all other things, to reign, to lay up Treasure, and to build, are at the most but little Appendixes, and little Props.
[tr. Cotton (1686)]

Man's great and glorious master-work is to live befittingly; all other things -- to reign, to lay up treasure, to build -- are at the best mere accessories and aids.
[tr. Ives (1925)]

Our great and glorious masterpiece is to live appropriately. All other things, ruling, hoarding, building, are only little appendages and props, at most.
[tr. Frame (1943)]

Our most great and glorious achievement is to live our life fittingly. Everything else -- reigning, building, laying up treasure -- are at most tiny props and small accessories.
[tr. Screech (1987)]