This is a commonplace of motivational self-help, e.g. the famous quote from Calvin Coolidge:
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. The slogan 'Press On' has solved and always will solve the problems of the human race.
Obviously, you need something worth persisting with. But the capacity for mental long-distance endurance is an important strength to have to achieve a goal.
(I have very little, fwiw.)
Determination pushes (pulls? drags? propels?) you along the path you planned on your current map of reality, but won't do you any good if your map doesn't match the territory, or the point you designated as a target is unreachable. That is, determination is useless without at least some epistemic rationality.
Yes. Here's his essay from October 2010 -- I wasn't aware of it when I posted the link:
What We Look for in Founders
1. Determination. This has turned out to be the most important quality in startup founders. We thought when we started Y Combinator that the most important quality would be intelligence. That's the myth in the Valley. And certainly you don't want founders to be stupid. But as long as you're over a certain threshold of intelligence, what matters most is determination. You're going to hit a lot of obstacles. You can't be the sort of person who gets demoralized easily.
Paul Graham of Y-Combinator on picking winners-at-life:
Paul Graham spills: Why some companies get his cash and others don't