"classical education" has been used to refer to a broad-based study of the liberal arts and sciences, in contrast to a practical or pre-professional program. A number of informal groups and professional organizations have led the classical education movement in the past century. Within the secular classical movement, Mortimer Adler and Robert Hutchins set forth the "Great Books" of Western civilization as the center stage for a classical education curriculum in the 1930s. Some public schools (primarily charters) have structured their curricula and pedagogy around the trivium and integrate the teaching of values (sometimes called "character education") into the mainstream classroom. Three phases of modern education linked to classical education The classical education movement has borrowed terms used in educational history to name three phases of education. "Primary education" teaches students how to learn. "Secondary education" then teaches a conceptual framework that can hold all human knowledge (history), fills in basic facts and practices of major fields of knowledge, and develops the fundamental skills of every major human activity. "Tertiary education" then prepares a person to pursue an educated profession such as law, theology, military strategy, medicine, or science. Primary education – the trivium Primary education is divided into three stages using terms introduced by Dorothy Sayers in her essay "The Lost Tools of Learning": "poll-parrot", "pert", and poetic". According to Sayers, these phases are roughly coordinated with human development and would ideally be coordinated with each individual student's development. Sayers connects her three stages with the three liberal language arts (trivium): grammar, logic, and rhetoric, respectively. While grammar, logic, and rhetoric are taught as subjects in classical schools, many schools also use these three arts as a paradigm for child development. Logic and rhetoric were often taught in part by the Socratic method, in which the teacher raises questions and the class discusses them. By controlling the pace, the teacher can keep the class very lively, yet disciplined. Grammar Grammar consists of language skills such as reading and the mechanics of writing. An important goal of grammar is to acquire as many words and manage as many concepts as possible so as to be able to express and understand clearly concepts of varying degrees of complexity. Classical education traditionally included study of Latin and Greek to reinforce understanding of the workings of languages and allow students to read the classics of western civilization untranslated. Logic Logic is the process