Essentialists believe that there is a common core of knowledge that needs to be transmitted to students in a systematic, disciplined way. The emphasis in this conservative perspective is on intellectual and moral standards that schools should teach. The core of the curriculum is essential knowledge and skills and academic rigor. Although this educational philosophy is similar in some ways to Perennialism, Essentialists accept the idea that this core curriculum may change. Schooling should be practical, preparing students to become valuable members of society. It should focus on facts on facts-the objective reality out there--and "the basics," training students to read, write, speak, and compute clearly and logically. Schools should not try to set or influence policies. Students should be taught hard work, respect for authority, and discipline. Teachers are to help students keep their non-productive instincts in check, such as aggression or mindlessness. This approach was in reaction to progressivist approaches prevalent in the 1920s and 30s William Bagley, took progressivist approaches to task in the journal he formed in 1934. Other proponents of Essentialism are: James D. Koerner (1959), H.G. Rickover (1959), Paul Copperman (1978), and Theodore Sizer (1985)