Brain or Heart?

Some of the biggest mistakes we make are due to making a decision with the brain rather than the heart   OR the other way around..  I find a pretty general rule of thumb works for me.  When dealing with people or animals, lead with your heart & when dealing with all other matters, particularly as related to business, lead with your brain.  Too often we let our emotions (heart) get in the way of deciding business matters and just as often we let our logic(brain) overshadow the humanness (heart) in our dealings with other living creatures.   So how does one accomplish this you may ask.   what works for me, Carl is to make my heart the default master of my decision making and try to  stop and think (brain) about business related matters before taking action on them.   At worse, you occasionally make a business decision  with your heart that may cost you, but I'd rather err on the side of humanness.   question is, how will YOU handle these situations?