 This strategy may seem fatal to analytic functionalism, which restricts itself to the use of a priori information to distinguish among mental states, since it's not clear that the information needed to distinguish among experiences such as color perceptions will result from conceptual analysis of our mental state terms or concepts. However, this problem may not be as dire as it seems. For example, if sensations and perceptual experiences are characterized in terms of their places in a “quality space” determined by a person's pre-theoretical judgments of similarity and dissimilarity (and perhaps also in terms of their tendencies to produce various emotional effects), then these characterizations may qualify as a priori, even though they would have to be elicited by a kind of “Socratic questioning”.