Progressive education is a reaction against the traditional style of teaching which teaches facts largely at the expense of understanding what is being taught. When you examine the teaching styles and curriculum of the 19th century, you understand why certain enlightened educators decided that there had to be a better way. A Brief Overview of Progressive Educationchronicles the influence of progressive educators such as John Dewey and William H. Kirkpatrick.
The progressive education philosophy embraces the idea that we should teach children how to think and that a test cannot measure whether or not a child is an educated person. The Calhoun School lays out the argument in Progressive Education. The philosophy is complete anathema to conservative educators who cling to outmoded ways of teaching. They would rather teach children what to think than teach children to think for themselves through a process of discovery.