When one instinctively picks winning stocks, we compliment the mind.
When a mother instinctively rushes to the kids' room, we cheer the mother's heart.
When one is tricked by an illusion, we chide the mind's eye.
When one is fooled into believing an illusion of love, we bemoan the heart's naiveté.
When one party tricks, we call his mind cunning.
When a party is tricked we call his a trusting heart.
When an individual admires the night sky & proceeds to understand the stars, we admire his mind.
When an individual admires the night sky & describes it in a poem, we sigh at his heart
When a man devises ways to make money, we call his mind shrewd.
When a man seeks ways to distribute his money, we call his heart generous.
Recalling a face, a memory, that night, the kindness - all of it is in the brain. Yet, we oust it from the podium where gentleness is celebrated. The minute the brain devises clever stratagems we declare it to be a work of the mind. The minute it recalls ardour & sobs we embrace the kind heart & proclaim that all that is good is not yet dead. Well, the heart that built the Taj Mahal also chopped off hands (a tale with no basis).
Kahneman in his seminal work on how the brain seems to work (primarily around decision theory) seems to indicate that what we popularly call of the heart is often in the realm of System 1 thinking of the mind. Nowhere does he call them out as mind & heart. Not that you must agree with him, but do give the poor scholar some credit.
I could well rush to call it all yin & yang & how a little of each stains the other & satisfy all our needs to be vague & placatory, but I am unable to draw a line where the mind ends & the heart begins, or vice versa. Sometimes kindness & sensitivity is a cultured response. An ignorant soul when exposed to the suffering of others, develops the requisite sensitivity & heart-felt, nay, mind-nurtured response. All our heart remains unaware of the predicament of cotton mill workers in Uzbekistan until we are exposed to their plight. Plenty of human sensitivity finds origin in education. Where a man is blamed for his uncouth behaviour, he is slighted for being poorly educated, a matter largely of the mind.
Where the mind is often pinned is in the vicinity of what Mr. Hofstadter calls "certain kinds of gooey lumps encased in hard protective shells mounted atop mobile pedestals that roam the world on pairs of slightly fuzzy, jointed stilts". The heart, safely, is bookmarked near the eponymous sanguine pump. While the mind is rational, cold, blood-thirsty & exacting in its measured persona, the heart is throbbing, warm, gentle, loving & so vaguely absent-minded in any measure & in every measure. One evokes sympathy & a billion dollar romance industry. The other evokes hushed objurgation & a multi-billion dollar industry of commerce & financial transactions. Where one lulls a babe to sleep, the other rings the young to rush to work.
It is difficult to exclude a scientific enquiry into this matter but I shall abstain to the fullest of my ability.
All our perceptions & observations are through our senses, rooted in the brain (I'd say the central nervous system as well, but let's call all that the "brain"). What the brain receives as stimuli the brain processes to distill as insight, learning and/or method. All exposure to this world is through the senses & most of our responses are our interpretive volley to those stimuli. If we leave hormonal responses of hunger, fear & sexual needs aside, we would not have a response had we not had a fermentation of our sensory loot. A babe cannot sigh till she has accumulated sufficient sense of irony or the ability to gather intensity till the point of climax. A babe has no concept of connect as she would connect to anyone who would feed. It is thus that adoption & surrogacy thrive as options.
Try this experiment with the most sensitive person you meet: In a monotone, explain the movie clip they are about to see. Tell them how everything ends well & the father saves his daughter. Make your friend aware that kids when asked how much they miss someone will more often than not throw their little arms wide open & that is cute & expected. They probably learnt it from their parents & recognised that it is considered cute (rewarded gestures). Explain each scene & dialogue & tear & smile throughout. Tell them how it was supposed to end well else there wouldn't be a movie to make of it. Then show them the movie interspersing it with "This is what I was referring to". The chances that this sensitive person will respond with all heart is fairly lower than when s/he was not made aware of the build up of emotions & climax. We are capable of that. We can want to stay under water to see how long we can hold our breath & emerge with a burst for fresh air. We love the rush of a culminating moment of emotion. We also love chocolate cake. And if you noticed, the child was just pleased, not emotional & all heart.
While all perceiving is through the window of the senses, how we assimilate all that flies in & how we synthesise it is individual & often not predictable. But repeatability is not the point here. Our innate sensitivity grooms & smudges what we receive into a notion & understanding of life creating a bouquet of responses which go by the name of "I". If the "I" cannot be located at a precise point two inches north-west of the navel, how did we ever get to decide whether "I" feel it in my heart or mind? You must have noted that I do not use the word brain save in the need to identify the collector of sensations. It is not the heart but a mix of how we hold perceived incidents & memory, allowing the same to curdle in the earthen pot of our soul (something that acts as a substrate as it doesn't govern what we receive as experience/events), that makes us who we are, both in demonstrations of intellectual ability as well as emotional capability.
If it is our brain's (and associated minions') window that gathers, if it is the soul, time & chance that brews what was gathered, if it is purely the assembly of life's events viewed through the entirety of being that creates a unique perspective, then where did we create the dichotomy between mind & heart? If we are comfortable saying that the heart thinks & vivisects, then let us simply address our varyingly dual personas as heart. If we cannot imagine the heart as inventing a new device, then let us say the mind feels & the mind thinks. Or pick another word! Just one!