“I propose to show my fellows a man as nature made him, and this man shall be myself.”

Love – That’s All Cary Grant Ever Thinks About (1964)
Context: I used to hide behind the façade that was Cary Grant … I didn’t know if I were Archie Leach, or Cary Grant, and I wasn’t taking any chances. … Another thing I had to cure myself of was the desire for adulation, and the approbation of my fellow man. It started when I was a small boy and played football at school. If I did well they cheered me. If I fumbled I was booed. It became very important to me to be liked. It’s the same in the theater, the applause and the laughter give you courage and the excitement to go on. I thought it was absolutely necessary in order to be happy. Now I know how it can change, just like that. They can be applauding you one moment, and booing you the next. The thing to know is that you have done a good job, then it doesn’t hurt to be criticized. My press agent was very indignant over something written about me not too long ago. “Look,” I told him. “I’ve known this character for many years, and the faults he sees in me are really the faults in himself that he hates.”

Attributed to Augustine by many sources on line, but without an actual reference.
Disputed

Sentence-Sermons from Brigham Young University Quarterly quoted in The Latter-Day Saints' Millenial Star, Vol. 70 https://books.google.com/books?id=eItJAAAAYAAJ&pg=PA452&lpg=PA452&dq=He+that+cheats+another+is+a+knave;+but+he+that+cheats+himself+is+a+fool.&source=bl&ots=WBAQiPjQX6&sig=WLEdKN2_kXPXj8jZALKCp2dguaQ&hl=en&sa=X&ved=0ahUKEwjXmNeF_7HMAhUH42MKHdySDgsQ6AEILzAE#v=onepage&q=fool&f=false

Source: A Dream of John Ball (1886), Ch. 4: The Voice of John Ball
Context: Forsooth, he that waketh in hell and feeleth his heart fail him, shall have memory of the merry days of earth, and how that when his heart failed him there, he cried on his fellow, were it his wife or his son or his brother or his gossip or his brother sworn in arms, and how that his fellow heard him and came and they mourned together under the sun, till again they laughed together and were but half sorry between them. This shall he think on in hell, and cry on his fellow to help him, and shall find that therein is no help because there is no fellowship, but every man for himself.

Sketches of Border Adventures, 1842

Source: (1932), p.2

Parallel Lives, Caesar

A Dictionary of Thoughts : Being A Cyclopedia Of Laconic Quotations from the Best Authors of the World, Both Ancient and Modern (1908) by Tryon Edwards, p. 327
Variant: I mean to make myself a man, and if I succeed in that, I shall succeed in everything else.

Markets, Governments, and the Common Good, speech at Hillsdale College (27 September 2007)
2000s
Context: Say that you hire me to mow your lawn and afterwards you pay me $30. What I have earned might be thought of as certificates of performance, i. e. proof that I served you. With these certificates of performance in hand, I visit my grocer and demand 3 pounds of steak and a six-pack of beer that my fellow man produced. In effect, the grocer asks, "Williams, you're demanding that your fellow man, as ranchers and brewers, serve you; what did you do in turn to serve your fellow man?" I say, "I mowed my fellow man’s lawn." The grocer says, "Prove it!" That's when I hand over my certificates of performance -- the $30.