A theory or myth regarding the origin of the universe, the earth, and living beings.
Attempts to create a naturalistic cosmogony are subject to two separate limitations. One is based in the philosophy of science and the epistemological constraints of science itself, especially with regards to whether scientific inquiry can ask questions of "why" the universe exists. Another more pragmatic problem is that there is no physical model that can explain the earliest moments of the universe's existence because of a lack of a consistent theory of quantum gravity. Also of interest are supernatural creation accounts, as in ancient Greek myth or in the Creationism of the Abrahamic religions.