Hume’s theory then needs to analyze what types of associative relations between Impressions mattered for determining the ordering of Ideas. Hume’s analysis consisted of three types of associative relations: cause and effect, contiguity, and resemblance. If two Impressions instantiated one of these associative relations, then their corresponding Ideas would mimic the same  instantiation.[6] For instance, if Impression IM1 was cotemporaneous with Impression IM2, then (ceteris paribus) their corresponding Ideas, ID1 and ID2, would become associated.