 There are various entities which, if they exist, would be candidates for necessary beings: God, propositions, relations, properties, states of affairs, possible worlds, and numbers, among others. Note that the first entity in this list is a concrete entity, while the rest are abstract  entities.[2]  Many interesting philosophical questions arise when one inquires about necessary beings: What makes it the case that they exist necessarily? Is there a grounding for their necessary existence? Do some of them depend on others? If so, how might one understand the dependence relation?