Heart vs Mind

I have this thought. What is more important? Heart or Mind?
Are they interlink? Do they go hand in hand or the opposite? Some wise person 'told' me that the heart is more vital than the mind. I have a sound mind not to rebutt after consideration though i have wanted to. I am surprise that i have 'trained' myself not to be impulsive which in the past i will surely flare up like firework.

I have made up my mind to do certain things but do i have the heart to proceed?
Many people always ask this question, is your mind sound or clear but do they ask if your heart is sound or clear? Why they often think of the mind first instead of the heart?
Perhaps, our hearts is just a machine that keeps us (human) going and working. When our heart cease to function, we are death but is our mind still operating?
Is this science ...........?

I have just commented on another blog, if i set my mind on doing something, i will have all the heart and soul to do it. Can i say that i have the heart to achieve but are mindless?
Wow, so many questions how to answer? Better don't crack my mind or i shall have headache and maybe heartache.......?