- But man is not made for defeat. A man can be destroyed but not defeated.
Ernest Hemingway 
- There is no failure except in no longer trying. There is no defeat except from within, no really insurmountable barrier save our own inherent weakness of purpose.
Frank McKinney “Kin” Hubbard 
- Because a fellow has failed once or twice, or a dozen times, you don't want to set him down as a failure till he's dead or loses his courage — and that's the same thing.
George Horace Lorimer 
- My great concern is not whether you have failed, but whether you are content with your failure.
- Abraham Lincoln 
Most of our obstacles would melt away if, instead of cowering before them, we should make up our minds to walk boldly through them."
- Orison Swett Marden
- The probability that we may fail in struggle ought not to deter us from the support of a cause we believe to be just
Abraham Lincoln 
- In great attempts it is glorious even to fail.
Vince Lombardi 
- What we call failure is not the falling down, but the staying down.
Mary Pickford 
- . . . The race is not [always] to the swift, nor the battle to the strong. . .
 [Ecclesiastes 9:11] Bible 
- Never give up. Never, never give up!. We shall go on to the end.
 Winston Churchill 
A man of sense is never discouraged by difficulties; he redoubles his industry and his diligence, he perseveres, and infallibly prevails at last.
 Lord Chesterfield 
-Good luck is another name for tenacity of purpose.
 Ralph Waldo Emerson 
-Victory is always possible for the person who refuses to stop fighting.
 Napoleon Hill 
-What we do not see, what most of us never suspect of existing, is the silent but irresistible power which comes to the rescue of those who fight on in the face of discouragement.
 Napoleon Hill 
- A leader, once convinced that a particular course of action is the right one, must....be undaunted when the going gets tough.
 Ronald Reagan 
We all die, The goal isnt to live forever, the goal is to create something that will.
-Anonymous
Ne Desit Virtus" ("Let Valor Not Fail")
187th Infantry Regiment
I am a little wounded; I am not slain, I shall lie myself down to bleed awhile, Then rise, to strive with you again!
-unknown
“In life you need either inspiration or desperation.”
-Anthony Robbins
“Desperation is the raw material of drastic change. Only those who can leave behind everything they have ever believed in can hope to escape.”
William S. Burroughs
"Despair is the price one pays for setting oneself an impossible aim"
- Graham Greene
“Never despair; but if you do, work on in despair”
- Edmund Burke
“We draw our strength from the very despair in which we have been forced to live. We shall endure.”
- unknown
The greatest oak was once a little nut who held its ground. 
- Unknown
Fall seven times, stand up eight.
- Japanese Proverb
When the world says, "Give up," Hope whispers, "Try it one more time."
- Unknown
He conquers who endures.
- Persius
Perseverance is the hard work you do after you get tired of doing the hard work you already did.
- Newt Gingrich
I may not be there yet, but I'm closer than I was yesterday.  
- Author Unknown
Don't be discouraged.  It's often the last key in the bunch that opens the lock.  
- Unknown
The woods are lovely, dark and deep,But I have promises to keep, and miles to go before I sleep
-Robert Frost
The effort to understand the universe is one of the very few things that lifts human life a little above the level of farce, and gives it some of the grace of tragedy.
- Steven Weinberg
"I do not feel obliged to believe that the same God who has endowed us with sense, reason, and intellect has intended us to forgo their use." 
- Galileo Galilei
Life being what it is, one dreams of revenge.   
- Paul Gauguin
We don't see things as they are, we see things as we are.
  - Anais Nin
You can discover what your enemy fears most by observing the means he uses to frighten you.
  - Eric Hoffer
What people say you cannot do, you try and find that you can. 
- Henry David Thoreau 
"If you are tired, keep going; if you are scared, keep going; if you are hungry; keep going; if you want to taste freedom, keep going."
- Harriet Tubman 
Never consider the possibility of failure; as long as you persist, you will be successful.
- Brian Tracy
“The unreal is more powerful than the real, because nothing is as perfect as you can imagine it.”
- Chuck Palahniuk
It's only after we've lost everything that we're free to do anything. 
Chuck Palahniuk, Fight Club 
So many of our dreams at first seem impossible, then they seem improbable, and then, when we summon the will, they soon become inevitable. 
- Christopher Reeve
The nice part about being a pessimist is that you are constantly being either proven right or pleasantly surprised. 
- George F. Will
"Nobody made a greater mistake than he who did nothing because he could do only a little."
- Edmund Burke
"A wise man can see more from the bottom of a well than a fool can from a mountain top ."
- unknown
"Happiness isn't something you experience; it's something you remember."
- Oscar Levant
"Any fool can know. The point is to understand."
- Albert Einstein