The antonyms for the word "hardheartednesses" are compassion, sensitivity, tenderness, kindness, and empathy. Someone who is compassionate and sensitive is able to understand and share the feelings of others, and is willing to help those who are in need. Tenderness refers to a gentle and caring attitude towards others, while kindness is a willingness to act with generosity and empathy towards others. Empathy, on the other hand, is the ability to understand and share the feelings of another person. These words represent the opposite of hardheartednesses, which is an attitude characterized by a lack of compassion, sensitivity, tenderness, kindness, and empathy towards others.