The antonyms for the word "heartlessnesses" are empathy, sympathy, compassion, kindness, warmth, generosity, and humanity. These words suggest an emotional intelligence that is absent in heartlessness. Empathy and sympathy imply the ability to understand and share the feelings of others. Compassion is the desire to alleviate the suffering of others. Kindness is the quality of being gentle, friendly, and generous. Warmth is the ability to convey affection and affectionate feelings. Generosity implies willingness to give and share without any expectation of return. Humanity suggests the quality of being civilized, compassionate, and benevolent. These antonyms are words that reflect the opposite of heartlessness, and inspire us to act with kindness and compassion towards others.