sentences:  The Bridge was a result of the culmination of the foundational work on Dianetics and Scientology training that Hubbard had established in the mid-1960s.In 1965, Hubbard published The Bridge to Freedom, which includes the “Classification and Gradation Chart,” which, according to new religious movement specialist James R. Lewis, discusses the steps that church members must follow as they learn and study Scientology.The chart was a summary of the results of Hubbard's experimentation since the Hubbard Dianetics Research Foundation was founded fifteen years before that time.