John Stuart Mill (May 20, 1806 – May 8, 1873) believed that both sexes should have equal rights under the law and that "until conditions of equality exist, no one can possibly assess the natural differences between women and men, distorted as they have been. What is natural to the two sexes can only be found out by allowing both to develop and use their faculties freely." Mill frequently spoke of this imbalance and wondered if women were able to feel the same "genuine unselfishness" that men did in providing for their families. This unselfishness Mill advocated is the one "that motivates people to take into account the good of society as well as the good of the individual person or small family unit". Similar to Mary Wollstonecraft, Mill compared sexual inequality to slavery, arguing that their husbands are often just as abusive as masters, and that a human being controls nearly every aspect of life for another human being. In his book "The Subjection of Women", Mill argues that three major parts of women's lives are hindering them: society and gender construction, education, and marriage. He also argues that sex inequality is greatly inhibiting the progress of humanity.