 Problems of the Nagelian model led to the development of alternative accounts based on the same basic idea, which actively incorporated the idea of levels into their framework (Hooker 1981; P.S. Churchland 1986; Schaffner 1993; Bickle 1998, 2003). This culminated in the “New Wave” model of reduction, where intertheoretic relations form a continuum ranging from complete elimination to retentive Nagel-style reduction (Bickle 1998). For a summary of this model, see the entry  scientific reduction  §2.6. In the present context, what is noteworthy is that the cases that inspire the eliminativist aspirations of the New Wave model encompass only intralevel, i.e., successive, relations, while the conclusions they draw concern cases of the interlevel kind (particularly the relationship between psychology and neuroscience; McCauley 1996). Historical cases of elimination, such as the replacement of the phlogiston theory with the caloric theory of heat, have arguably all been cases where a theory is replaced by a successor at roughly the same level of organization. Theories at different levels of organization can coevolve and exert selective pressures on each other’s terminology, practices, explanations, and such (Wimsatt 1976b [2007: 252]; P.S. Churchland 1986: 363, 373), but this rarely if ever results in elimination or replacement of one of the theories.