Educational freedom was provided by the constitution of 1831, the first law for public elementary education was not passed until 1842. In 1914 compulsory attendance was enacted for children between the ages of 6 and 14; compulsory schooling now extends to age 18. Since 1959 the education system has included state secular schools and private Roman Catholic schools. Educational controversies involving language and religion that arose in Belgium in the 19th century have continued to the present day. Almost the entire adult population is literate. The oldest Belgian university dates from the Middle Ages. The Catholic University of Leuven, since 1970 divided into independent French- and Dutch-speaking universities, was founded under religious auspices in 1425.