Loyal Rue has written: Religious naturalists will be known for their reverence and awe before Nature, their love for Nature and natural forms, their sympathy for all living things, their guilt for enlarging the ecological footprints, their pride in reducing them, their sense of gratitude directed towards the matrix of life, their contempt for those who abstract themselves from natural values, and their solidarity with those who link their self-esteem to sustainable living. Varieties The literature related to religious naturalism includes many variations in conceptual framing. This reflects individual takes on various issues, to some extent various schools of thought, such as basic naturalism, religious humanism, pantheism, panentheism, and spiritual naturalism that have had time on the conceptual stage, and to some extent differing ways of characterizing Nature. The current discussion often relates to the issue of whether belief in a God or God-language and associated concepts have any place in a framework that treats the physical universe as its essential frame of reference and the methods of science as providing the preeminent means for determining what Nature is. There are at least three varieties of religious naturalism, and three similar but somewhat different ways to categorize them. They are: An approach to naturalism using theological language but fundamentally treats God metaphorically. An approach to naturalism using theological language, but as either (1) a faith statement or supported by philosophical arguments, or (2) both, usually leaving open the question whether that usage as metaphor or refers to the ultimate answer that Nature can be. Neo-theistic (process theology, progressive religions) – Gordon Kaufman, Karl E. Peters, Ralph Wendell Burhoe, Edmund Robinson Non-theistic (agnostic, naturalistic concepts of god) – Robertson himself, Stanley Klein, Stuart Kauffman, Naturalistic Paganism. Atheistic (no God concept, some modern naturalism, Process Naturalism, C. Robert Mesle, non-militant atheism, antitheism) – Jerome A. Stone, Michael Cavanaugh, Donald A. Crosby, Ursula Goodenough, Daniel Dennett, and Carol Wayne White A miscellany of individual perspectives – Philip Hefner The first category has as many sub-groups as there are distinct definitions for god. Believers in a supernatural entity (transcendent) are by definition not religious naturalists, however the matter of a naturalistic concept of God (Immanence) is currently debated. Strong atheists are not considered religious naturalists in this differentiation. Some individuals call themselves religious naturalists but refuse to be categorized. The unique theories of religious naturalists Loyal Rue, Donald A. Crosby, Jerome A. Stone, and