This proposal is an intent to explain the evolution of secondary education curricula in some western countries (mainly England, France and Germany) over a long century, approximately from 1870 to nowadays. The method is basically a literature review, except for the last period, for which it leans on some primary data out of a survey on teachers, which has been made at the beginning of the
21th century.
The main hypothesis is that secondary education curricula depend on the access to secondary
education, that is: the percentage of an age group acceding to secondary education.