Steve Kaufman in a recent post on lifehack http://www.lifehack.org/articles/lifehack/set-ambitious-goals-but-learn-to-accept-what-you-achieve.html stated that success begins in the mind. I disagree. The heart brings the motivation, will and perseverance to succeed. I know this from personal experience and simply watching the smaller, slower, and weaker football player consistently make hit and make tackles when the more 'talented' give up. The mind is poweful, but losing heart is everything.