"Cosmology is derived from Greek words meaning "doctrine of the world" and refers to that part of METAPHYSICS which deals with the origin and structure of the universe. The earliest and most influential cosmologies were those of Plato (c. 427-347 B.C.) and Aristotle (384-322 B.C.). Although Christian theologians modified them in the light of their own doctrines of CREATION and PROVIDENCE, the problems discussed by the two great Greek philosophers - the origins of matter, the relationship of time to ETERNITY, the laws of the world, etc., - remained the standard problems for centuries. With the rise of the sciences of astronomy and of physics and the accompanying skepticism concerning the possibility of solving cosmological problems by speculative reasoning (in contrast to scientific reasoning and experiment), many of the old problems of Cosmology became scientific problems, and those that remained, like the problems of evil, were generally made metaphysical or ontological problems. Cosmology, in general, is no longer a concern of most modern philosophers, and what is sometimes called Cosmology is not a theory of the origin and structure of the universe so much as it is a scheme of categories said to be applicable to everything that is, i.e., it is ontology."
source: A Handbook of Theological Terms
Next week, we shall delve into what is Ontology, and ontological arguments. :)