Natural religion most frequently means the "religion of nature", in which God, the soul, spirits, and all objects of the supernatural are considered as part of nature and not separate from it. Conversely, it is also used in philosophy, specifically Roman Catholic philosophy, to describe some aspects of religion that are said to be knowable apart from divine revelation through logic and reason alone (see natural theology and Deism), for example, the existence of the unmoved Mover, the first cause of the universe.