As Quote Investigator explains, allegories about animals doing impossible things have been incredibly popular in the past century. But no, this one isn't from Einstein. (Source: http://quoteinvestigator.com/2013/04/06/fish-climb/.)
Misattributed
Variant: Everybody is a genius. But if you judge a fish by its ability to climb a tree, it will live its whole life believing that it is stupid.
Quotes about trees
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“Between every two pine trees there is a door leading to a new way of life.”
Muir's marginal note in volume I of Prose Works by Ralph Waldo Emerson (This volume is located at the Beinecke Rare Book and Manuscript Library of Yale University. See Albert Saijo, "Me, Muir, and Sierra Nevada", in Reinhabiting a Separate Country: A Bioregional Anthology of Northern California, edited by Peter Berg, San Francisco, California: Planet Drum Foundation, 1978, pages 52-59, at page 55, and Frederick W. Turner, Rediscovering America: John Muir in His Time and Ours (1985), page 193.)
1870s
“Moments like this are buds on the tree of life. Flowers of darkness they are.”
Source: Mrs. Dalloway
“Why are there trees I never walk under but large and melodious thoughts descend upon me?”
“Trees cause more pollution than automobiles do.”
in a letter from Bordighera to friends in Paris, Jan. 1884; as cited in: Joslyn Art Museum, Holliday T. Day, Hollister Sturges (1987), Joslyn Art Museum: Paintings and Sculpture from the European and American Collections, p. 100
1870 - 1890
“Autumn wind rises, white clouds fly.
Grass and trees wither; geese go south.”
The Autumn Wind 127 BC (translated by Arthur Waley), Dictionary of Quotations, Chambers: Edinburgh, U.K, 2005, p. 930
Quote
Søren Kierkegaard The Concept of Anxiety, Nichol p. 98-100 (1844)
About
As forests are cleared and species vanish, there's one other loss: a world of languages http://www.theguardian.com/environment/2014/jun/08/why-we-are-losing-a-world-of-languages
"Field and Future of Traveling Libraries". Home Education Department. Bulletin. State University of New York (1901), (40).
Letter to Deborah Webster (25 October 1958)
"Strange Fruit" (1939). Though Holiday's renditions made this anti-lynching song famous, it was written by Abel Meeropol (using his pseudonym "Lewis Allen").
Misattributed
In 'Art News', April 1965, p. 63; as quoted in in The Paintings of Joan Mitchel, ed. Jane Livingstone, Joan Mitchell, Linda Nochlin, p. 26
1950 - 1975
Commenting on After the Fall (1964) in The Saturday Evening Post (1 February 1964)
“Anger is a weed; hate is the tree.”
58
Sermons
Nichts ist weniger verheißend als Frühreife; die junge Distel sieht einem zukünftigen Baume viel ähnlicher als die junge Eiche.
Source: Aphorisms (1880/1893), p. 27.
Mythopoeia (1931)
The Wild Swans At Coole http://poetry.poetryx.com/poems/1712/, st. 1
The Wild Swans at Coole (1919)
Source: Culture and Value (1980), p. 44e
On one of his pseudonom, Gyakyo Rojin. He may have said the above in his late life definitely, since he began to use the name Gwakyo Rojin in 1843.
Attributed
Source: Earthsea Books, A Wizard of Earthsea (1968), Chapter 5
On Truth and Lie in an Extra-Moral Sense (1873)
Sejamos simples e calmos,
Como os regatos e as árvores,
E Deus amar-nos-á fazendo de nós
Belos como as árvores e os regatos,
E dar-nos-á verdor na sua primavera,
E um rio aonde ir ter quando acabemos...
E não nos dará mais nada, porque dar-nos mais seria tirar-nos mais.
Alberto Caeiro (heteronym), O Guardador de Rebanhos ("The Keeper of Sheep"), VI — in A Little Larger Than the Entire Universe, trans. Richard Zenith (Penguin, 2006)
The Alexiad, Preface
Letter to James F. Morton (1929), quoted in "H.P. Lovecraft, a Life" by S.T. Joshi, p. 483
Non-Fiction, Letters, to James Ferdinand Morton, Jr.
The Notebooks of Leonardo da Vinci (1883), XXI Letters. Personal Records. Dated Notes.
"Ghetto Prisoners"
On Albums, I Am... (1999)
40.
För levande och döda (For the Living and the Dead) 1996
“Knowing trees, I understand the meaning of patience. Knowing grass, I can appreciate persistence.”
Countryman: A Summary of Belief, Lippincott, 1965, p. 99
As When You Were a Child.
För levande och döda (For the Living and the Dead) 1996
“You get tragedy where the tree, instead of bending, breaks.”
1929, p. 1
Culture and Value (1980)
Did Adam have a Bellybutton?: And other tough questions about the Bible (2000)
Genjūan no Fu ("Prose Poem on the Unreal Dwelling") in Donald Keene, Anthology of Japanese Literature, p. 374 (Translation: Donald Keene)
Statements
“Slowly the evening changes into the clothes
held for it by a row of ancient trees.”
Der Abend wechselt langsam die Gewänder,
die ihm ein Rand von alten Bäumen hält.
Abend (Evening) (as translated by Cliff Crego)
Das Buch der Bilder (The Book of Images) (1902)
Deep Thoughts: Inspiration for the Uninspired (1992), Berkley Books, ISBN 0-425-13365-6
Concepts
“A man as he ought to be: that sounds to us as insipid as "a tree as it ought to be."”
Sec. 332 (Notebook W II 3. November 1887 - March 1888, KGW VIII, 2.304, KSA 13.62)
The Will to Power (1888)
Biblical Series IV: Adam and Eve: Self-Consciousness, Evil, and Death https://www.youtube.com/watch?v=Ifi5KkXig3s
Upon visiting the grave of Johann de Kalb, some years after his death, as quoted in "Baron De Kalb" https://books.google.com/books?id=40wyAQAAMAAJ&pg=PA96&dq=%22Would+to+God+he+had+lived+to+share+its+fruits%22&hl=en&sa=X&ei=2IoZVa3XLuyasQTXiIDoCg&ved=0CB0Q6AEwAA#v=onepage&q=%22Would%20to%20God%20he%20had%20lived%20to%20share%20its%20fruits%22&f=false (1827), by George R. Graham and Edgar Allan Poe, Graham's Illustrated Magazine of Literature, Romance, Art, and Fashion, Volume 2, Watson, p. 96.
Posthumous attributions
“My wife is on a new diet. Coconuts and bananas. She hasn't lost weight, but can she climb a tree.”
"The Haunted Smile: The Story of Jewish Comedians in America" (2001)
And somehow, it was God. I wasn't sure that it was… just something cool and dark and clean.
God Dies (1931)
In a letter to a friend, Nice 1918, as quoted in 'Matisse & Picasso', Paul Trachtman, Smithsonian Magazine, February 2003, p. 6
1910s
<span class="plainlinks"> In Midnight Street http://www.prachyareview.com/poems-by-suman-pokhrel/</span>
From Poetry
Source: Culture and Value (1980), p. 52e
The Notebooks of Leonardo da Vinci (1883), XX Humorous Writings
Nobel Lecture (1998)
“Way Down South in Dixie
(Break the heart of me)
They hung my black young lover
To a cross roads tree.”
"Song for a Dark Girl" (l. 1-4), from Fine Clothes to the Jew (1927)
Concepts
"New Songs for After the Tears", from Revolt of a Newborn (1973)
“When there is a big tree small ones climb on its back to reach the sun.”
Source: No Longer at Ease (1960), Chapter 10 (p. 95)
“People who try to explain pictures are usually barking up the wrong tree.”
Quoted in Picasso on Art (1988), ed. Dore Ashton.
Attributed from posthumous publications
Bartlett's Familiar Quotations, 10th ed. (1919), Maxims
Source: Dictionary of Burning Words of Brilliant Writers (1895), P. 145.
Letter to Joseph Huey (6 June 1753); published in Albert Henry Smyth, The Writings of Benjamin Franklin, volume 3, p. 145.
Epistles
Gottlob Frege, Montgomery Furth (1964). The Basic Laws of Arithmetic: Exposition of the System. p. 10
“A tree's a tree. How many more do you need to look at?”
Opposing expansion of Redwood National Park, as quoted in Sacramento Bee (3 March 1966)
1960s
“God loved the birds and invented trees. Man loved the birds and invented cages.”
Quoted in Barbara K. Rodes and Rice Odell, A Dictionary of Environmental Quotations (1992), p. 22
2015, Remarks to the People of Africa (July 2015)
“I like trees because they seem more resigned to the way they have to live than other things do.”
Part II, Ch. 8
O Pioneers! (1913)
Variant: Fruitful earth drinks up the rain, Trees from earth drink that again; The sea too drinks the air, the sun Drinks the sea, and him the moon. Is it reason, then, do ye think, That I should thirst when all else drink?
Source: Odes, 21.
Source: 1930s-1951, Philosophical Occasions 1912-1951 (1993), Ch. 7 : Remarks on Frazer's Golden Bough, p. 131