Teaching is changing and it is being forced to change by many forces of social change. Today’s theory and practice of teaching in adult and higher education are not only shaped by technology, but also by prevalent teaching and learning theories such as constructivism, progressive principles of education, humanism and even behaviorism. While behaviorism, a major component of pedagogical teaching, successfully dominated adult and higher education in the past, the purpose of this chapter is to demonstrate that we are experiencing a paradigm shift from being pedagogical in our instruction to an andragogical mode of education in the 21st century due to the fact that we do know, to some extent, how students learn. Therefore, the way knowledge is delivered in the new century must be changed in order to serve the needs of this learning society.