Leonardo Boff is the founder of the liberation theology movement. He entered the Franciscan Order in 1959 and was ordained a priest in 1964. After receiving his PhD from the University of Munich in 1970, he served as Professor of Systematic Theology at the Franciscan Institute of Theology in Petrópolis-Rio de Janeiro and Professor of Philosophy of Religion and Ethics at the University of the State of Rio de Janeiro. He is a co-author of the Earth Charter and the author of more than eighty works, including Jesus Christ Liberator: A Critical Christology for Our Time; Church, Charisma and Power: Liberation Theology and the Institutional Church; Ecology: Cry of the Earth, Cry of the Poor; and Essential Care: An Ethics of Human Nature.