I think of few heroic actions, which cannot be traced to the artistical impulse. He who does great deeds, does them from his innate sensitiveness to moral beauty.
I am a man who, sauntering along without fully stopping, turns a casual look upon you and then averts his face, Leaving it to you to prove and define it, Expecting the main things from you. ~ Leaves of Grass
It is a beautifultruth that all men contain something of the artist in them. And perhaps it is the case that the greatest artists live and die, the world and themselves alike ignorant what they possess. Who would not mourn that an ample palace, of surpassingly graceful architecture, fill’d with luxuries, and embellish’d with fine pictures and sculpture, should stand cold and still and vacant, and never be known or enjoy’d by its owner? Would such a fact as this cause your sadness? Then be sad. For there is a palace, to which the courts of the most sumptuous kings are but a frivolous patch, and, though it is always waiting for them, not one of its owners ever enters there with any genuine sense of its grandeur and glory. I think of few heroicactions, which cannot be traced to the artistical impulse. He who does great deeds, does them from his innate sensitiveness to moral beauty.
Talk not so much, then, young artist, of the great old masters, who but painted and chisell’d. Study not only their productions. There is a still higher school for him who would kindle his fire with coal from the altar of the loftiest and purest art. It is the school of all grand actions and grand virtues, of heroism, of the death of patriots and martyrs — of all the mighty deeds written in the pages of history — deeds of daring, and enthusiasm, devotion, and fortitude.
"Talk to an Art-Union (A Brooklyn fragment)" (1839)
This is what you shall do: Love the earth and sun and the animals, despise riches, give alms to every one that asks, stand up for the stupid and crazy, devote your income and labor to others, hate tyrants, argue not concerning God, have patience and indulgence toward the people, take off your hat to nothing known or unknown or to any man or number of men, go freely with powerful uneducated persons and with the young and with the mothers of families, read these leaves in the open air every season of every year of your life, re examine all you have been told at school or church or in any book, dismiss whatever insults your own soul, and your very flesh shall be a great poem and have the richest fluency not only in its words but in the silent lines of its lips and face and between the lashes of your eyes and in every motion and joint of your body. . . . The poet shall not spend his time in unneeded work. He shall know that the ground is always ready ploughed and manured . . . . others may not know it but he shall. He shall go directly to the creation. His trust shall master the trust of everything he touches . . . . and shall master all attachment.
In our sun-down perambulations, of late, through the outer parts of Brooklyn, we have observed several parties of youngsters playing "base", a certain game of ball...Let us go forth awhile, and get better air in our lungs. Let us leave our close rooms...the game of ball is glorious.
From the July 23, 1846 edition of the Brooklyn Daily Eagle, quoted in Florence Bernstein Freedman, Walt Whitman Looks at the Schools (READ BOOKS, 2007, ISBN 1406731889), pp. 126-127 
I have just this moment heard from the front — there is nothing yet of a movement, but each side is continually on the alert, expecting something to happen.
O Mother, to think that we are to have here soon what I have seen so many times, the awful loads and trains and boatloads of poor, bloody, and pale and wounded young men again — for that is what we certainly will, and before very long. I see all the little signs, getting ready in the hospitals, etc.; it is dreadful when one thinks about it. I sometimes think over the sights I have myself seen: the arrival of the wounded after a battle, and the scenes on the field, too, and I can hardly believe my own recollections. What an awful thing war is! Mother, it seems not men but a lot of devils and butchers butchering each other.
Letter to his mother (22 March 1864)
We Americans have yet to really learn our own antecedents, and sort them, to unify them. They will be found ampler than has been supposed, and in widely different sources. Thus far, impress'd by New England writers and schoolmasters, we tacitly abandon ourselves to the notion that our United States has been fashion'd from the British Islands only, and essentially form a second England only — which is a very great mistake.
"Some people are so much sunlight to the square inch. I am still bathing in the cheer he radiated."
Conversation with Whitman (16 May 1888) as quoted in With Walt Whitman in Camden (1906) by Horace Traubel, Vol. I
I said: "Baseball is the hurrah game of the republic!" He was hilarious: "That's beautiful: the hurrah game! well — it's our game: that's the chief fact in connection with it: America's game: has the snap, go fling, of the American atmosphere — belongs as much to our institutions, fits into them as significantly, as our constitutions, laws: is just as important in the sum total of our historic life."
Conversation with Whitman (4 July 1889) as quoted in With Walt Whitman in Camden (1906) by Horace Traubel, Vol. IV
If the United States haven't grown poets, on any scale of grandeur, it is certain that they import, print, and read more poetry than any equal number of people elsewhere -- probably more than the rest of the world combined.
Poetry (like a grand personality) is a growth of many generations -- many rare combinations.
To have great poets, there must be great audiences too.
Quotes reported in Bartlett's Familiar Quotations, 10th ed. (1919).
I will write the evangel-poem of comrades and of love.
Starting from Paumanok, 6
I say the real and permanent grandeur of these States must be their religion.
Starting from Paumanok. 7
I say the whole earth and all the stars in the sky are for religion’s sake.
Starting from Paumanok. 7
None has begun to think how divine he himself is and how certain the future is.
Starting from Paumanok. 7
Nothing can happen more beautiful than death.
Starting from Paumanok. 12
I loafe and invite my soul.
Song of Myself, 1
I have no mockings or arguments; I witness and wait.
Song of Myself, 4
In the faces of men and women I see God.
Song of Myself, 48
I sound my barbaric yawp over the roofs of the world.
Song of Myself, 52
I see Hermes, unsuspected, dying, well-beloved, saying to the people, "Do not weep for me,
This is not my true country, I have lived banished from my true country—I now go back there,
I return to the celestial sphere where every one goes in his turn."
Salut au Monde, 6
Each of us inevitable;
Each of us limitless—each of us with his or her right upon the earth.
Salut au Monde, 11
The great city is that which has the greatest man or woman.
Song of the Broad-Axe
In this broad earth of ours,
Amid the measureless grossness and the slag,
Enclosed and safe within its central heart,
Nestles the seed perfection.
Song of the Universal, 1
All, all for immortality,
Love like the light silently wrapping all.
Song of the Universal, 4
Youth, large, lusty, loving—Youth, full of grace, force, fascination!
Do you know that Old Age may come after you, with equal grace, force, fascination?
Youth, Day, Old Age and Night
Roaming in thought over the Universe, I saw the little that is Good steadily hastening towards immortality,
And the vast that is evil I saw hastening to merge itself and become lost and dead.
Roaming in Thought, 1
Thunder on! Stride on! Democracy. Strike with vengeful stroke!
Drum-Taps. Rise O Days from your fathomless Deep, 3
Not houses of peace are you, nor any nor all of their prosperity; if need be you shall have every one of those houses to destroy them;
You thought not to destroy those valuable houses, standing fast, full of comfort, built with money;
May they stand fast then? Not an hour, unless you, above them and all, stand fast.
Drum-Taps. Song of the Banner at Daybreak
Over all the sky—the sky! far, far out of reach, studded with the eternal stars.
Drum-Taps. Bivouac on a Mountain-side
Give me the splendid silent sun, with all his beams full-dazzling!
Drum-Taps. Give me the splendid Silent Sun
Lo! the moon ascending!
Up from the East, the silvery round moon;
Beautiful over the house-tops, ghastly, phantom moon;
Immense and silent moon.
Drum-Taps. Dirge for Two Veterans
Beautiful that war and all its deeds of carnage, must in time be utterly lost;
That the hands of the sisters Death and Night incessantly softly wash again and ever again, this soiled world.
When lilacs last in the door-yard bloomed,
And the great star early drooped in the western sky in the night,
I mourned, and yet shall mourn with ever-returning spring.
Memories of President Lincoln, 1
Come lovely and soothing death,
Undulate round the world, serenely arriving, arriving,
In the day, in the night, to all, to each,
Sooner or later, delicate death.
Memories of President Lincoln, 14
Praised be the fathomless universe
For life and joy and for objects and knowledge curious;
And for love, sweet love—But praise! O praise and praise
For the sure-enwinding arms of cool-enfolding Death.
Memories of President Lincoln, 14
O Captain! my Captain! our fearful trip is done!
The ship has weathered every wrack, the prize we sought is won,
The port is near, the bells I hear, the people all exulting.
Memories of President Lincoln. O Captain! my Captain!
Liberty is to be subserved, whatever occurs.
To a Foiled European Revolutionaire
Peace is always beautiful.
The Sleepers, 7
What do you suppose will satisfy the soul except to walk free and own no superior?
Laws for Creations
To me every hour of the light and dark is a miracle,
Every cubic inch of space is a miracle.
I was thinking the day most splendid, till I saw what the not-day exhibited;
I was thinking this globe enough, till there sprang out so noiseless around me myriads of other globes.
Night on the Prairies
I see that I am to wait for what will be exhibited by death.
Night on the Prairies
I swear I think there is nothing but immortality!
To think of Time, 9
The paths to the house I seek to make,
But leave to those to come the house itself.
Thou Mother with thy Equal Brood, 1
Society waits unformed and is between things ended and things begun.
Now obey thy cherished secret wish,
Embrace thy friends—leave all in order;
To port and hawser's tie no more returning,
Depart upon thy endless cruise, old Sailor!
Now Finalè to the Shore (To Tennyson)
I announce the great individual, fluid as Nature, chaste, affectionate, compassionate, fully armed;
I announce a life that shall be copious, vehement, spiritual, bold,
And I announce an end that shall lightly and joyfully meet its translation.
While consistently attributed to Whitman, this popular motivational quote has no source. It is occasionally listed as occurring in Leaves of Grass, but the closest phrase found in that collection is "Be not curious about God."
I see great things in baseball, It will take our people out-of-doors, fill them with oxygen, give them a larger physical stoicism, tend to relieve us from being a nervous, dyspeptic set, repair those losses and be a blessing to us.
This has been widely attributed to Whitman, and no one else, but without definite source. It has sometimes been cited as being from the Brooklyn Daily Eagle (sometimes with a date of 23 July 1846), where Whitman had been an editor, but its presence on that date is not apparent in the online historical archives of that publication.
"I like your interest in sports ball, chiefest of all base-ball particularly: base-ball is our game: the American game: I connect it with our national character. Sports take people out of doors, get them filled with oxygen generate some of the brutal customs (so-called brutal customs) which, after all, tend to habituate people to a necessary physical stoicism. We are some ways a dyspeptic, nervous set: anything which will repair such losses may be regarded as a blessing to the race. We want to go out and howl, swear, run, jump, wrestle, even fight, if only by so doing we may improve the guts of the people: the guts, vile as guts are, divine as guts are!" "Sports for a Dyspeptic Race", Intimate With Walt: Whitmans Conversataions With Horace Traubel, p. 261
Yes, Mexico must be thoroughly chastised! Let our arms now be carried with a spirit which shall teach the world that, while we are not forward for a quarrel, American knows how to crush, as well as expand!
Editorial comment identified as from the Brooklyn Daily Eagle (11 May 1846)
Incompossible,adj. Unable to exist if something else exists. Two things are incompossible when the world of being has scope enough for one of them, but not enough for both—as Walt Whitman's poetry and God's mercy to man.
Whitman...a man full-blooded and brotherly, unselfconscious in his democracy and genuinely at ease with all kinds and classes.
Gerald Bullett, "Walt Whitman", in Alfred Barratt Brown, Great Democrats, 1934.
I am not blind to the worth of the wonderful gift of "LEAVES OF GRASS." I find it the most extraordinary piece of wit and wisdom that America has yet contributed. I am very happy in reading it, as great power makes us happy. It meets the demand I am always making of what seemed the sterile and stingy nature, as if too much handiwork, or too much lymph in the temperament, were making our western wits fat and mean. I give you joy of your free and brave thought. I have great joy in it. I find incomparable things said incomparably well, as they must be. I find the courage of treatment which so delights us, and which large perception only can inspire. I greet you at the beginning of a great career, which yet must have had a long foreground somewhere, for such a start. I rubbed my eyes a little, to see if this sunbeam were no illusion; but the solid sense of the book is a sober certainty. It has the best merits, namely, of fortifying and encouraging…
Ralph Waldo Emerson, in a letter to Whitman, thanking him for a copy of Leaves of Grass (21 July 1855)
I always knew in my heart Walt Whitman’s mind to be more like my own than any other man’s living. As he is a very great scoundrel this is not a pleasant confession.
One Whitman is miracle enough, and when he comes again it will be the end of the world.
Randall Jarrell, in "Some Lines from Whitman" in Poetry and the Age (1953), p. 119
I know the formal element in Walt Whitman's poetry found and enormous echo throughout the world. Yet Walt Whitman's significance lies elsewhere. He combined the contemplation of nature and of civilization which are apparently either contradictory, into a single intoxicating vision of life, because he always had sight of the transitoriness of all phenomena. He said: "Living is the little that is left over from dying." so he gave his whole heart to every leaf of grass. I admire in him the reconciliation of art and nature. When the war between the Northern and Southern States in America, which first really set in motion the power of our present machine world, first broke out, Walt Whitman became a medical orderly. He did what all of us ought to do, particularly today. He helped the weak, the sick and the defeated. He was a Christian and–with a close affinity to us Jews–he was therefore an important measure of the status and worth of humanity.
Franz Kafka qtd. in Gustav Janouch Conversations with Kafka (1971), p. 167
Behold great Whitman, whose licentious line
Delights the rake, and warms the souls of swine;
Whose fever'd fancy shuns the measur'd pace,
And copies Ovid's filth without his grace.
In his rough brain a genius might have grown,
Had he not sought to play the brute alone;
But void of shame, he let his wit run wild,
And liv'd and wrote as Adam's bestial child.
Averse to culture, strange to humankind,
He never knew the pleasures of the mind.
Scorning the pure, the delicate, the clean,
His joys were sordid, and his morals mean.
Thro' his gross thoughts a native vigour ran,
From which he deem'd himself the perfect man:
But want of decency his rank decreas'd,
And sunk him to the level of the beast.
Would that his Muse had dy'd before her birth,
Nor spread such foul corruption o'er the earth.
H. P. Lovecraft, in an "Essay on Modern Poets" this was published as a "Fragment on Whitman” in The Ancient Track (2001) edited by S. T. Joshi, p. 192
I make a pact with you, Walt Whitman — I have detested you long enough.
Rob Riemen, recalling a conversation with Joseph Goodman, Nobility of Spirit : A Forgotten Ideal (2008), p. xxvii
Whitman to me is the most fascinating of American poets. Whitman started to write the great poetry from scratch after he had written all that junk for newspapers, the sentimental lyrical poems. All of a sudden he wrote Leaves of Grass. When I was teaching at the University of Nebraska, my friend James Miller was chairman of the English Department. He wrote the first book attempting to make a parallel between the structure of Leaves of Grass and the steps of the mystical experience as in St. John of the Cross. I was completely bowled over by this, not having been able to explain how Whitman came to write “Song of Myself,” which is unlike anything not only in American literature, but unique in all the world. The parallels to it are mystical literature. Miller tried to show that there was actual evidence for this kind of experience, which evidently happens at a particular moment in someone’s life. … When I saw the negative reaction to Whitman with the great ruling critics of the time, I couldn’t believe it. Eliot never really gave up hammering away on Whitman, neither did Pound. Although Pound makes little concessions. Whitman, you know, didn’t have any influence in this country until Allen Ginsberg came along.
I would think Walt Whitman probably had more influence on my whole poetic thinking than anybody, but I never dreamed of trying to write in the Whitman manner.
Karl Shapiro, in "Karl Shapiro, The Art of Poetry No. 36", interviewed by Robert Phillips in Paris Review No. 99 (Spring 1986)
When I was young I once found a book in a Dutch translation, 'The leaves of Grass'. It was the first time a book touched me by its feeling of freedom and open spaces, the way the poet spoke of the ocean by describing a drop of water in his hand. Walt Whitman was offering the world an open hand (now we call it democracy) and my 'Monument for Walt Whitman' became this open hand with mirrors, so you can see inside yourself.
Karel Appel, as quoted in ‘Karel Appel – the complete sculptures’, eds. Harry de Visser / Roland Hagenberg, Edition Lafayette, New York 1990, p. 93