 Does one need states of affairs in addition to facts and thoughts? Yes, there seem to be good reasons to posit states of affairs as a sui generis category of object. If states of affairs are to be useful (i) they must exist even if they do not obtain and (ii) must involve objects and properties (relations) directly. (i) is the basic feature that distinguishes states of affairs from facts; (ii) the basic feature that distinguishes them from thoughts. Therefore a theory of states of affairs must answer the question how a state of affairs can “involve” objects and properties (relations) and combine them, if the objects don’t exemplify the properties (stand in the relations). Although there are promising proposals to answer it, this question is still open.