Darwin was intrigued by his half-cousin Francis Galton's argument, introduced in 1865, that statistical analysis of heredity showed that moral and mental human traits could be inherited, and principles of animal breeding could apply to humans. In "The Descent of Man", Darwin noted that aiding the weak to survive and have families could lose the benefits of natural selection, but cautioned that withholding such aid would endanger the instinct of sympathy, "the noblest part of our nature", and factors such as education could be more important. When Galton suggested that publishing research could encourage intermarriage within a "caste" of "those who are naturally gifted", Darwin foresaw practical difficulties, and thought it "the sole feasible, yet I fear utopian, plan of procedure in improving the human race", preferring to simply publicise the importance of inheritance and leave decisions to individuals.</ref> Francis Galton named this field of study "eugenics" in 1883. After Darwin's death, his theories were cited to promote eugenic policies.