 At its extreme, a mysterian may hold that no first-order theory of the Trinity is possible, so we must be content with delineating a consistent “grammar of discourse” about the Trinity, i.e., policies about what should and shouldn’t be said about it. In this extreme form, mysterianism may be a sort of sophisticated position by itself—to the effect that one repeats the creedal formulas and refuses on principle to explain how, if at all, one interprets them. More common is a moderate form, where mysterianism supplements a Trinity theory which has some understandable content, but which is vague or otherwise problematic. Thus, mysterianism is commonly held as a supplement to one of the theories of sections 1–3. Again, it may serve as a supplement not to a full-blown theory (i.e., to a literal model of the Trinity) but rather to one or more (admittedly not very helpful) analogies. (See  section 3.3.1  in the supplementary document on the history of trinitarian doctrines.) Unitarian views on the Father, Son, and Spirit are typically motivated in part by hostility to mysterianism. (See the supplementary document on  unitarianism.)  But the same can said of many of the theories of sections 1–3.