 There are three main approaches to theories of the initial state, all of which have been pursued by cosmologists since the late 60s in different forms. Expectations for what a theory of initial conditions should achieve have been shaped, in particular, by inflationary cosmology. Inflation provided a natural account of the three otherwise puzzling features of the initial state emphasized in the previous section. Prior to inflation, these features were regarded as “enigmas” (Dicke &amp; Peebles 1979), but after inflation, accounting for these features has served as an eligibility requirement for any proposed theory of the early universe.