 Some have seen in the appeal to criteria nothing but a form of behaviorism. Chihara and Fodor (1965) are among such philosophers, and their work has served to turn the tide against talk of criteria as a way of understanding the relationship between mental states and behavior. Chihara and Fodor sum up the Wittgensteinian argument as follows: if we are justified in claiming that one can tell or determine that a predicate ‘Y’ applies on the basis of the presence of X then either X is a criterion of Y or X can be shown to be correlated with Y. They then claim that this overlooks the possibility that in some cases the justification for the application of a predicate rests on an appeal to the “simplicity, plausibility and predictive adequacy of an explanatory system as a whole” (1965: 411). They point out that scientists use this method of explanation when it comes to the detection of particles that are not directly observable (see  §1.2).  Chihara and Fodor agree with the Wittgensteinian who holds that the child does not learn about mental states by introspection but rather learns about complex relations between mental states and behavior in the course of learning her language, but they point out that part of what the child learns is how to explain another’s behavior by reference to her thoughts and feelings and suggest that this may be the result either of explicit training or of an innate capacity.