As 'persistence' it is that tension within us that launches us into nothingness, unknown territory, when it seems likely we will fail in the attempt.
Why? Because stubbornness doesn't give in.
Stubbornness means not giving up, despite solid incentives to do so.
Stubbornness is what we cling to when all we have left is a vague sense of purpose or direction and a ton of fear.
Stubbornness leads to success and achievement.
So be stubborn! Persist.