Not observation of a duty but liberty itself is the pledge that assures fidelity.

Ellen Karolina Sofia Key (Swedish: [kej]; December 11 1849 – April 25 1926) was a Swedish difference feminist writer on many subjects in the fields of family life ethics and education and was an important figure in the Modern Breakthrough movement. She is best known for her book on education Barnets århundrade (1900) which was translated in English in 1909 as The Century of the Child.