John Stuart Mill had a difficult childhood, as his father used him as a subject to test his theories of education, which caused Mill to have a nervous breakdown. As an adult, Mill fought against various forms of tyranny, including advocating for women's rights. He argued that women's subordination to men through practices like coerced marriage was a barbaric holdover that should be abolished. Mill believed that individuals require freedom to develop themselves on all sides according to their inner nature, rather than being shaped like machines to some external model.