Nothing in the world can take the place of persistence.Talent will not; nothing is more common than unsuccessful men with talent.Genius will not; unrewarded genius is almost a proverb.Education will not; the world is full of educated derelicts.Persistence and determination alone are omnipotent.
If a man will begin with certainties,he shall end with doubts;but if he will be content to begin with doubts,he shall end in certainties.
I had a linguistics professor who said that it's man's ability to use language that makes him the dominant species on the planet. That may be. But I think there's one other thing that separates us from animals