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)
                                    
Help us to complete the source, original and additional information
Jean Jacques Rousseau 91
Genevan philosopher 1712–1778Related quotes
“We are socialists. Let us hope that it will not have been in vain.”
Prussianism and Socialism (1919)
“I am a simple Buddhist monk — no more, no less.”
As quoted in Nobel Prize Winners (1991) by Lisa F. Dewitt.
                                        
                                        XVIII, p. 484 
1810s, Letters to John Taylor (1814)
                                    
“To say more while saying less is the secret of being simple.”
                                        
                                         Simplicity http://www.poetrysoup.com/famous/poem/21390/Simplicity 
From the poems written in English
                                    
2010-, Ai Weiwei Says Blind Dissident’s Escape Will Inspire Chinese, 2012
“Let us say, rather, that actors are a necessary evil,”
                                        
                                        Regarding his oft-cited quote stating that actors are cattle; as paraphrased and quoted in  "Town Called Hollywood: Director Pleads Off Poundage" http://www.mediafire.com/view/ix2ammmxkb3flqx/Screen%20Shot%202018-09-11%20at%2012.56.17%20AM.png by Philip K. Scheuer, in The Los Angeles Times (30 May 1943). 
Context: [T]he director passed off the phrase as one of his "Machiavellian quips," not to be taken seriously. "Let us say, rather, that actors are a necessary evil," he cautioned, with a straight face. "As a matter of fact, I couldn't work if I weren't on friendly terms with them; I'll bend over backward every time. Besides, I get into each picture I make, if only for a couple of seconds—so I'm probably a frustrated actor at heart myself."
                                    
“And less is often more, as Lessing's Prince teaches us.”
                                        
                                        Und minder ist oft mehr, wie Lessings Prinz uns lehrt. 
"Neujahrswunsch", in Der Teutsche Merkur (January 1774) p. 4; translation from The Quote…Unquote Newsletter (October 1997) p. 3. 
The phrase "Less is more" was later used by Robert Browning, and by Mies van der Rohe.