Matthieu Ricard — French Clergyman born on February 15, 1946,

Matthieu Ricard is a French writer and Buddhist monk who resides at Shechen Tennyi Dargyeling Monastery in Nepal... (wikipedia)

Negative emotions like hatred destroy our peace of mind.
Empathy is the faculty to resonate with the feelings of others. When we meet someone who is joyful, we smile. When we witness someone in pain, we suffer in resonance with his or her suffering.
Neuroscience has proven that similar areas of the brain are activated both in the person who suffers and in the one who feels empathy. Thus, empathic suffering is a true experience of suffering.
Mind training is based on the idea that two opposite mental factors cannot happen at the same time. You could go from love to hate. But you cannot, at the same time - toward the same object, the same person - want to harm and want to do good.
That's what Buddhism has been trying to unravel - the mechanism of happiness and suffering. It is a science of the mind.