Eugenic policies have been conceptually divided into two categories. Positive eugenics is aimed at encouraging reproduction among the genetically advantaged; for example, the reproduction of the intelligent, the healthy, and the successful. Possible approaches include financial and political stimuli, targeted demographic analyses, "in vitro" fertilization, egg transplants, and cloning. Negative eugenics aimed to eliminate, through sterilization or segregation, those deemed physically, mentally, or morally "undesirable". This includes abortions, sterilization, and other methods of family planning. Both positive and negative eugenics can be coercive; in Nazi Germany, for example, abortion was illegal for women deemed by the state to be fit.