 For Astell, though ideas can be confused, they are not the sources of error. Rather, Astell locates falsity and error in judgments, and often in language (Astell 2002, 169, 171). She holds that judgment involves the comparison of two ideas and that sometimes we lack an “intermediate idea” (a “middle term”) in order to make a judgment (Astell 2002, 146–7, 172–3).