These three words (among others, such as, desire and determination) are often debated in terms of their relevance to success.
Here are some readings that I found particularly interesting (I plan on adding to the list periodically) on the subject of “success”:
-Fortune article: Why Talent is Overrated
-Boston.com article: The Truth About Grit
-Marc Andreessen on Productivity: The Pmarca Guide to Personal Productivity