What is love, hate, and emotion?

Scientists have largely answered this question already, but as with most neuroscience, the details remain fuzzy. It is quite clear from decades of research that everything we feel, whether it be sensation or emotion, is mediated by the release of molecules, largely neuropeptides, between synapses in the brain.

Dopamine, serotonin, epinephrine, and a large cadre of other small molecules act as the signals between our brain cells. Our understanding is growing piecemeal, but as with the emergence of consciousness, soon we will hopefully be able to synthesize a complete model of emotion, including not only happiness, anger, sadness, joy, fear, and courage, but also spiritual experiences, amazement, and euphoria.

Daniel D. Brown.
lifeboat.com