Quotations about:
    caution

Dear sire, and offspring worthy of your fire!
We bards are dupes to what ourselves admire.
Would I be brief — I grow confused and coarse;
Who aims at smoothness, fails in fire and force;
In him who soars aloft, bombast is found;
Who fears to face the tempest, crawls aground.
Who courts variety and fain would ring
A thousand changes on the self-same string,
Will paint, as ’twere in fancy’s wildest mood
Boars in the wave and dolphins in the wood.
Thus even error, shun’d without address,
Breeds error, diff’rent in its kind, not less.

[Maxima pars vatum, pater et iuvenes patre digni,
decipimur specie recti: brevis esse laboro,
obscurus fio; sectantem levia nervi
deficiunt animique; professus grandia turget;
serpit humi tutus nimium timidusque procellae:
qui variare cupit rem prodigialiter unam,
delphinum silvis adpingit, fluctibus aprum:
in vitium ducit culpae fuga, si caret arte.]

Horace (65–8 BC) Roman poet, satirist, soldier, politician [Quintus Horatius Flaccus]

Epistles [Epistularum, Letters], Book 2, ep. 3 “Art of Poetry [Ars Poetica; To the Pisos],” l. 24ff (2.3.24-31) (19 BC) [tr. Howes (1845)]
    (Source)

(Source (Latin)). Other translations:

The more deale of us Poets, both the olde, and younge most parte,
Are ofte begylde by shewe of good, affectinge to muche arte.
I laboure to be verye breife, it makes me verye harde.
I followe flowinge easynes, my style is clearely marde
For lacke of pith and saverye sence, Write loftie, thou shalte swell:
He creepes by the grounde to lowe, afrayde with stormie vayne to mell.
He that in varyinge one pointe muche would bringe forth monstruouse store,
Would make the dolphin dwell in wooddes and in the flud the bore.
The shunning of a faulte is such that now and then it will
Procure a greater faulte, if it be not eschewde by skill.
[tr. Drant (1567)]

The greater part, that boast the Muses fire
Father, and sons right worthy of your Sire,
Are with the likenesse of the truth beguil'd:
My selfe for shortnesse labour, and am stil'd
Obscure. Another striving smooth to runne,
Wants strength, and sinewes, as his spirits were done;
His Muse professing height, and greatnesse, swells;
Downe close by shore, this other creeping steales,
Being over-safe, and fearing of the flaw:
So he that varying still affects to draw
One thing prodigiously, paints in the woods
A Dolphin and a Boare amidst the floods:
The shunning vice, to greater vice doth lead,
If in th'escape an artlesse path we tread.
[tr. Jonson (1640), l. 33ff]

Most Poets fall into the grossest faults,
Deluded by a seeming Excellence:
By striving to be short, they grow Obscure,
And when they would write smoothly they want strength,
Their Spirits sink; while others that affect,
A lofty Stile, swell to a Tympany;
Some timerous wretches start at every blast,
And fearing Tempests, dare not leave the Shore.
Others in love with wild variety,
Draw Boars in Waves, and Dolphins in a Wood;
Thus fear of Erring, joyn'd with want of Skill,
Is a most certain way of Erring still.
[tr. Roscommon (1680)]

But oft, our greatest errors take their rise
From our best views. I strive to be concise;
I prove obscure. My strength, my fire decays,
When in pursuit of elegance and ease.
Aiming at greatness, some to fustian soar;
Some in cold safety creep along the shore,
Too much afraid of storms; while he, who tries
With ever-varying wonders to surprise,
In the broad forest bids his dolphins play,
And paints his boars disporting in the sea.
Thus, injudicious, while one fault we shun,
Into its opposite extreme we run.
[tr. Francis (1747)]

Lov'd sire! lov'd sons, well worthy such a sire!
Most bards are dupes to beauties they admire.
Proud to be brief, for brevity must please,
I grow obscure; the follower of ease
Wants nerve and soul; the lover of sublime
Swells to bombast; while he who dreads that crime,
Too fearful of the whirlwind rising round,
A wretched reptile, creeps along the ground.
The bard, ambitious fancies who displays,
And tortures one poor thought a thousand ways,
Heaps prodigies on prodigies; in woods
Pictures the dolphin, and the boar in floods!
Thus ev'n the fear of faults to faults betrays,
Unless a master-hand conduct the lays.
[tr. Coleman (1783)]

The great majority of us poets, father, and youths worthy such a father, are misled by the appearance of right. I labor to be concise, I become obscure: nerves and spirit fail him, that aims at the easy: one, that pretends to be sublime, proves bombastical: he who is too cautious and fearful of the storm, crawls along the ground: he who wants to vary his subject in a marvelous manner, paints the dolphin in the woods, the boar in the sea. The avoiding of an error leads to a fault, if it lack skill.
[tr. Smart/Buckley (1853)]

Ye worthy trio! we poor sons of song
Oft find 'tis fancied right that leads us wrong.
I prove obscure in trying to be terse;
Attempts at ease emasculate my verse;
Who aims at grandeur into bombast falls;
Who fears to stretch his pinions creeps and crawls;
Who hopes by strange variety to please
Puts dolphins among forests, boars in seas.
Thus zeal to 'scape from error, if unchecked
By sense of art, creates a new defect.
[tr. Conington (1874)]

We poets, most of us, by the pretence,
Dear friends, are duped of seeming excellence.
We grow obscure in striving to be terse;
Aiming at ease, we enervate our verse;
For grandeur soaring, into bombast fall,
And, dreading that, like merest reptiles crawl;
Whilst he, who seeks his readers to surprise
With common things shown in uncommon wise,
Will make his dolphins through the forests roam.
His wild boars ride upon the billows' foam.
So unskilled writers, in their haste to shun
One fault, are apt into a worse to run.
[tr. Martin (1881)]

The greater part of us poets, O ye Father and Sons worthy of your parent, deceive ourselves under our illusion of what is right. I strive to write briefly, and so write obscurely. Compositions of a smooth nature argue a writer's deficiency both in force and spirit. An attempt at great subjects swells into bombast. A too cautious writer, and dreader of opposition, confines himself to common things. One who desires to amplify a single theme in an extravagant way, puts a dophin innto a wood, and a wild boar into the sea. The avoidance of one error, if unguarded by art, leads to another.
[tr. Elgood (1893)]

Most of us poets are misled by insistence upon our idea of what is right. I try to be brief and I become obscure; aiming at smoothness, we lose in vigor and spirit; attempting the sublime, we become turgid. Timid of the storm, we crawl along the ground. Thus if one lacks art, the over careful avoidance of one fault leads to another.
[tr. Dana/Dana (1911)]

Most of us poets, O father and ye sons worthy of the father, deceive ourselves by the semblance of truth. Striving to be brief, I become obscure. Aiming at smoothness, I fail in force and fire. One promising grandeur, is bombastic; another, overcautious and fearful of the gale, creeps along the ground. The man who tries to vary a single subject in monstrous fashion, is like a painter adding a dolphin to the woods, a boar to the waves. Shunning a fault may lead to error, if there be lack of art.
[tr. Fairclough (Loeb) (1926)]

Most of us poets -- O father, and sons worthy of your father, -- are misled by our idea of what is correct. I try to be terse, and end by being obscure; another strives after smoothness, to the sacrifice of vigour and spirit; a third aims at grandeur, and drops into bombast; a fourth, through an excess of caution and fear of squalls, goes creeping along the ground. He who is bent on lending variety to a theme that is by nature uniform, so as to produce an unnatural effect, is like a man who paints a dolphin in a forest or a wild boar in the waves. If artistic feeling is not there, mere avoidance of a fault leads to some worse defect.
[tr. Blakeney; ed. Kramer, Jr. (1936)]

O father, and sons who deserve a father like yours,
We poets are too often tricked into trying to achieve
A particular kind of perfection: I studiously try
To be brief, and become obscure; I try to be smooth,
And my vigor and force disappear; another assures us
Of something big which turns out to be merely pompous.
Another one crawls on the ground because he's too safe,
Too much afraid of the storm. The poet who strives
To vary his single subject in wonderful ways
Paints dolphins in woods and foaming boars on the waves.
Avoiding mistakes, if awkwardly done, leads to an error.
[tr. Palmer Bovie (1959)]

Most poets, father and young men deserving such a father,
go wrong in trying to be right: I struggle for concision,
I wind up being obscure; others try for smoothness
and lose strength, or for sublimit, and get gas.
One poet, too cautious, fears storms and craws along,
the other craves bizarre variety in a single subject
and paints a dolphin in a forest, a boar among the waves.
Fear of criticism leads to faults if we lack art.
[tr. Fuchs (1977)]

Most poets, leaders and led,
Chase a will-o’-the-wisp of abstract Right.
Thus:
I aim
at concision,
I hit
on darkness.
I aim to be smooth, my lines go slack.
The eloquent idealist rants and raves,
The timid, the gutless, crawl like beetles,
Seekers after novelty hang dolphins in trees,
Float a boar in the sea:
O rare effects!
O marvelous.
Ugh.
[tr. Raffel (1983 ed.)]

Father and worthy sons, we poets often
Know what we're aiming at, and often we miss.
I try my best to be terse, and I'm obscure;
I try for mellifluous smoothness, smooth as can be,
And the line comes out as spineless as a worm;
One poet, aiming for grandeur, booms and blusters;
Another one, scared, creeps his way under the storm;
And another, desiring to vary his single theme
In wonderful ways, produces not wonders but monsters --
Dolphins up in the trees, pigs in the ocean.
If you don't know what you're doing you can go wrong
Just out of trying to do your best to do right.
[tr. Ferry (2001)]

Poets in the main (I’m speaking to a father and his excellent sons)
are baffled by the outer form of what’s right. I strive to be brief,
and become obscure; I try for smoothness, and instantly lose
muscle and spirit; to aim at grandeur invites inflation;
excessive caution or fear of the wind induces groveling.
The man who brings in marvels to vary a simple theme
is painting a dolphin among the trees, a boar in the billows.
Avoiding a fault will lead to error if art is missing.
[tr. Rudd (2005 ed.)]

Most poets (dear sir, and you sons worthy of your sire),
Are beguiled by accepted form. I try to be brief
And become obscure: aiming at smoothness I fail
In strength and spirit: claiming grandeur he’s turgid:
Too cautious, fearing the blast, he crawls on the ground:
But the man who wants to distort something unnaturally
Paints a dolphin among the trees, a boar in the waves.
Avoiding faults leads to error, if art is lacking.
[tr. Kline (2015)]