Mechanists also emphasize the distinction between a how-possibly schema and a how-actually-enough schema (Craver and Darden 2013). A how-possibly schema describes how entities and activities might be organized to produce a phenomenon. A how possibly model is n hypothesis about how the mechanism works. Such models might be true (enough) or false. A true (enough) how-possibly model is (though we may not know it) also a how-actually (enough) model. A how-actually-enough schema describes how entities and activities are in fact organized to produce the phenomenon. The term “how-actually-enough” captures the idea that the requisite “accuracy” of a mechanistic model can vary considerably from one pragmatic context to another (Weisberg 2013).A false how possibly model is merely a how possibly model; just-so-stories are merely how possibly models (Dray 1957; Brandon 1985). Used in this way, the term “how possibly model” is similar to the term “hypothesis”: it is entertained as a possibility but not necessarily endorsed.