Brute facts and classical theism
The modal cosmological argument , or MCA, deals with the concepts of necessity and contingency. I'll leave more formalized versions for your reference here and here . For this post, it'll be sufficient to summarize it as follows: Something that could exist in a different state or fail to exist at all is contingent , in that its state of existence must be explained by something else, such as another contingent thing. For example, a chair is a contingent object. It could have different properties (i.e., be a different type of chair) or not exist at all. It was brought into existence by something else, such as a carpenter. There can't be an infinite regress of contingent things, otherwise the existence of the contingent set is not explained. Therefore, the existence of the contingent set must be explained an entity whose existence is explained by its own necessity. There's a lot of nuance in these arguments that is beyond the depth of this post — the semantics