Some authors, however, have emphasized similarities between Christian meditation and non-Christian meditation. Psychologist Daniel Goleman gives an overview of many styles of meditation in "The Varieties of the Meditative Experience", and includes a section on what he believes are key commonalities (as well as differences); he argues that all share the goal of the cultivation of attention. Thomas Merton, an American Catholic monk, believed Christianity had forsaken its mystical tradition in favor of Cartesian emphasis on rationality and concepts. Eastern traditions, for Merton, were mostly untainted by this type of thinking and thus had much to offer in terms of how to think of and understand oneself. Having studied the Desert Fathers and other Christian mystics, Merton found many parallels between the language of these Christian mystics and the language of Zen philosophy. This said, Merton felt non-Christian religions had little or nothing to contribute in terms of doctrine.