Heart

Metaphors are great for people in understanding concepts quickly. But HEART is one of those metaphors that needs a revamp. Heart is courage, or understanding, or love, or kindness, or gentleness, or ad nauseum. English is big enough to offer a new word for each of the qualities incorporated by HEART. We need to adopt new metaphors because what does it mean when someone says, "Think with your heart, not your head." I know that originated before all the scientific revolution as did all of the meanings of heart mentioned above. Since that revolution, though, we have words like sensitivity if that is what the saying is asking one to have.

I give up. Use worn-out metaphors. Just know that you haven't articulated very well. Eventually you will have to get around to saying what you really meant.