 Von Eckardt Klein applies this analysis to a neurological case study involving a controversial reinterpretation of  agnosia.[14]  Her philosophical explication of this important neurological method reveals that most challenges to localization arguments either argue only against the localization of a particular type of functional capacity or against generalizing from localization of function in one individual to all normal individuals. (She presents examples of each from the neurological literature.) Such challenges do not impugn the validity of standard arguments for functional localization from deficits. It does not follow that such arguments are unproblematic. But they face difficult factual and methodological problems, not logical ones. Furthermore, the analysis of these arguments as involving a type of functional analysis and inference to the best available explanation carries an important implication for the biological study of cognitive function. Functional analyses require functional theories, and structurally adequate functional analyses require checks imposed by the lower level sciences investigating the underlying physical mechanisms. Arguments to best available explanation are often hampered by a lack of theoretical imagination: the available alternative explanations are often severely limited. We must seek theoretical inspiration from any level of investigation or explanation. Hence making explicit the “logic” of this common and historically important form of neurological explanation reveals the necessity of joint participation from all scientific levels, from cognitive psychology down to molecular neuroscience. Von Eckardt Klein (1978) thus anticipated what came to be heralded as the “co-evolutionary research methodology”, which remains a centerpiece of neurophilosophy to the present day (see  section 6).