Brace thee, my friend, when times are hard, to show
A mind unmoved; nor less, when fair thy state,
A sober joy. For Death doth wait
As surely, whether woe
Dogs all thy days, or fortune bids thee bask
On peaceful lawn reclined while life goes well,
And quaff thy wine, from inner cell
Drawn at Falernian cask.

[Aequam memento rebus in arduis
servare mentem, non secus in bonis
ab insolenti temperatam
laetitia, moriture Delli,
seu maestus omni tempore vixeris
seu te in remoto gramine per dies
festos reclinatum bearis
interiore nota Falerni.]

Horace (65-8 BC) Roman poet and satirist [Quintus Horacius Flaccus]

Odes [Carmina], Book 2, # 3, l. 1ff (2.3.1-8) (23 BC) [tr. Marshall (1908)]
    (Source)

Generally believed to be addressed to Quintus Dellius, but some scholars point to an older manuscript that refers to "Gelli" rather than "Delli," which then fits into various theories about themes in in Horace's works.

(Source (Latin)). Alternate translations:

Keep still an equal minde, not sunk
With stormes of adverse chance, not drunk
With sweet Prosperitie,
O Dellius that must die,
Whether thou live still melancholy,
Or stretcht in a retired valley;
Make all thy howers merry
With bowls of choicest Sherrie.
[tr. Sir R. Fanshaw; ed. Brome (1666)]

An even mind in every State,
Amidst the Frowns and Smiles of Fate,
Dear mortal Delius always show;
Let not too much of cloudy Fear,
Nor too intemperate joys appear
Or to contract, or to extend thy Brow:
Whether thy dull unhappy Years
Run slowly clog'd with Hopes and Fears,
And sit too heavy on thy Soul;
Or whether crown'd on Beds of Flowers
Mirth softly drives thy easy hours
And cheers thy Spirits with the choicest Bowl.
[tr. Creech (1684)]

An equal mind, when storms o'ercloud,
Maintain, nor 'neath a brighter sky
Let pleasure make your heart too proud,
O Dellius, Dellius! sure to die,
Whether in gloom you spend each year,
Or through long holydays at ease
In grassy nook your spirit cheer
With old Falernian vintages.
[tr. Conington (1872)]

O Dellius, since thou art born to die, be mindful to preserve a temper of mind even in times of difficulty, as well an restrained from insolent exultation in prosperity: whether thou shalt lead a life of continual sadness, or through happy days regale thyself with Falernian wine of the oldest date, at ease reclined in some grassy retreat.
[tr. Smart/Buckley (1853)]

Let not the frowns of fate
Disquiet thee, my friend,
Nor, when she smiles on thee, do thou, elate
With vaunting thoughts, ascend
Beyond the limits of becoming mirth,
For, Dellius, thou must die, become a clod of earth!
 
Whether thy days go down
In gloom, and dull regrets.
Or, shunning life's vain struggle for renown,
Its fever and its frets,
Stretch'd on the grass, with old Falernian wine.
Thou giv'st the thoughtless hours a rapture all divine.
[tr. Martin (1864)]

With a mind undisturbed take life's good and life's evil,
Temper grief from despair, temper joy from vainglory;
For, through each mortal change, equal mind,
O my Dellius, befits mortal-born,
Whether all that is left thee of life be but trouble,
Or, reclined at thine ease amid grassy recesses,
Thy Falernian, the choicest, records
How serenely the holidays glide.
[tr. Bulwer-Lytton (1870)]

An even mind in days of care,
And in thy days of joy to bear
A chastened mood, remember: why?
'Tis, Dellius, that thou hast to die.
Alike, if all thy life be sad,
Or festal season find thee glad,
On the lone turf at ease recline,
And quaff thy best Falernian wine.
[tr. Gladstone (1894)]

See thou preserve a true equanimity
In seasons adverse, and in prosperity
A mind restrain'd from overweening
Joy, for, my Dellius, thou art mortal!
Whether in sorrow all thy life long thou live,
Or in a distant glade on some holiday,
Thou lie at ease, the summer day long,
Quaffing the specially-mark'd Falernian.
[tr. Phelps (1897)]

An even mind remember to preserve
In arduous times, conversely, in the good
One tinctured with no overweening joy.
For you will die (Gillo)
Whether you live at all times sad,
Or whether on distant lawn reclined
Through days of feast you are made glorious
From inmost cellar of Falernian.
[tr. Garnsey (1907)]

Remember, when life’s path is steep, to keep an even mind, and likewise, in prosperity, a spirit restrained from over-weening joy, Dellius, seeing thou art doomed to die, whether thou live always sad, or reclining in grassy nook take delight on holidays in some choice vintage of Falernian wine.
[tr. Bennett (Loeb) (1912)]

Remember, Dellius, doomed to die
Some day, to keep a level mind
When times are hard, nor pridefully
Exalt your horn when Fate seems kind --
Aye, doomed to die, whether each dawn
Renews your griefs, or days of rest
Comfort you, couched on some far lawn,
With old Falernian of the best.
[tr. Mills (1924)]

Maintain an unmoved poise in adversity;
Likewise in luck one free of extravagant
Joy. Bear in mind my admonition,
Dellius. Whether you pass a lifetime
Prostrate with gloom, or whether you celebrate
Feast-days with choice old brands of Falernian,
Stretched out in some green, unfrequented
Meadow, remember your death is certain.
[tr. Michie (1963)]

Remember, Dellius: keep yourself in
Balance when it’s hard, keep yourself in
Balance when all of it comes your way,
All of us destined to die
Whether we live forever sad
Or always lying in some grassy spot,
Celebrating life away
With a jug of choice Falernian.
[tr. Raffel (1983)]

When things are bad, be steady in your mind;
Dellius, don't be
Too unrestrainedly joyful in good fortune.
You are going to die.
It doesn't matter at all whether you spend
Your days and nights in sorrow,
Or, on the other hand, in holiday pleasure,
Drinking Falernian wine
Of an excellent vintage year, on the river bank.
[tr. Ferry (1997)]

Remember, entrapped in life’s bitter maze,
to keep an even mind. Even in prosperity
do not give way to unbridled joy.
Remember, you must die, O Dellius,
Whether you live always embrued in melancholy
or languidly laying in a far-off meadow
on festive days, you take delight in
some choice vintage of Falernian wine.
[tr. Alexander (1999)]

When things are troublesome, always remember,
keep an even mind, and in prosperity
be careful of too much happiness:
since my Dellius, you’re destined to die,
whether you live a life that’s always sad,
or reclining, privately, on distant lawns,
in one long holiday, take delight
in drinking your vintage Falernian.
[tr. Kline (2015)]