From the Stanford Encyclopedia of Philosophy article on the subject:
The cosmological argument is less a particular argument than an argument type. It uses a general pattern of argumentation (logos) that makes an inference from certain alleged facts about the world (cosmos) to the existence of a unique being, generally identified with or referred to as God. Among these initial facts are that certain beings or events in the world are causally dependent or contingent, that the universe (as the totality of contingent things) is contingent in that it could have been other than it is, that the Big Conjunctive Contingent Fact possibly has an explanation, or that the universe came into being. From these facts philosophers infer deductively, inductively, or abductively by inference to the best explanation that a first or sustaining cause, a necessary being, an unmoved mover, or a personal being (God) exists that caused and/or sustains the universe. The cosmological argument is part of classical natural theology, whose goal has been to provide evidence for the claim that God exists.
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