Hume's argument to distinguish between kindness and self-love lies in the investigation of his moral principle, and Hume accuses skeptical philosophers who deny the existence of moral differences. I doubt that he or she is so indifferent that he or she can not distinguish between good and evil. Hume believes that the differences between males arise from nature, customs and education. Hume believes that it can not claim that there is absolutely no moral difference, no matter how skeptical or skeptical.
In his study of the principle of self-love, Hume did not reject all aspects of egoist of justice and lack of kindness in human motives. He acknowledges many motives in human nature and explains the mixing of elements in our nature with the metaphor of pigeons, wolves and snakes. In principle, he regards mankind in the field of moral behavior as a mixture of kindness and self-love. Egoist believes that human beings are limited to the pursuit of survival, fear, ambition, and happiness, but Hume believes that motives of people are all kinds of generosity and generous passion. He insists that these factors vary from person to person. Because there is no unique information about that person, there is no way to know whether that person usually dominates and controls self-love or vice versa.
Hume's moral psychology and ethics make sympathetic motives important in moral life. He believes that the natural kindness mostly explains his so-called moral origin. The main theme is defending his mercy as a principle of humanity, as opposed to the theory of psychological self-interest. In Hume's moral theory, many people are directed to the theory of Mandeville (probably Hobbes) that human motive behaviors are private interests and humans are neither good nor kind to communication. Hume believes that self-interest is based on wrong moral psychology, and we consider that kindness is a "primitive" feature of human nature. Kindness is the most important principle of Hum's human morality, but he also uses the word "compassion" to identify virtue rooted in good will, generosity and love for others. Hume found kindness in many performances such as friendship, charity, compassion.