 Anstey (2000: 103) takes this to be a retreat from the relational theory. Curley (1972: 448–50) finds Boyle ambiguous and mistaken. Stewart (1991: xiv) holds that instability in Boyle’s use of terms precludes a definitive interpretation. However, Kaufman (2006) argues that the dispositive sense is consistent with the relational theory and as Boyle says, part of his defense of it. As Kaufman sees it, the theory of qualities is a consequence of Boyle’s method in natural philosophy, especially his commitment to reasoning from nothing but observational data and antipathy to a priori argumentation. It is possible here to give only a rough sketch of two important points of this interesting, detailed, and complicated interpretation.