A heart throbs so the carrier of the pulsating organ may continue to maintain simple exercizes required for existence. Breathing, seeing, hearing and walking are the quickest to come to mind in terms of basic function. Running, speaking and grabbing are next. With this, the animated object can sustain and even flourish. Further, as resources become plentiful permitting time to think, instead of hide or hunt, the heart does something more.

Longs for a companion

Yearns for touch

Breaks for loss

How does a heart do that?

How do we know that it does more than just pump vital blood to the far reaches of the human or inhuman anatomy?

What measurement was used to formulate this phenomena that is so common in every day life?

Questions with speculative answers only, yet so widely believed. Answers that boarder on the rediculous but are eagerly substantiated with authoritative command. 

Does the heart in love make the mind see sunlight, everywhere? Yes it does!

Does the heart that bereaves loss see darkness around every corner? most often!

Heart throbs must be more than that, they must pulse unseen and unheard signals to awaiting recepticles ready to color vision with enthusiastic hope or shade it with daunting distraught.

Hmm, the heart, how wierd! 

Kind of like Religion...