An interpretation is provided of the philosopher L. Wittgenstein's analyses of mental states. The theoretical implications of these analyses for cognitive development and qualitatively oriented researchers are discussed. The mental states examined are: (1) pain; (2) remembering; (3) calculating/adding; (4) following a rule; and (5) reading. Wittgenstein proposes that mental states have their origins in the activities of daily life and the shared agreements of community rather than a priori mental conditions. By setting mental states into the routines of daily life, Wittgenstein takes the position that mental states are products of the relations between the individual and the social world. Mental states are conceptualized as primary and secondary language games. Primary language games consist of shared activities open to public view, while secondary language games are those that take place within the mind, as thinking skills. As an example, it is suggested that individuals learn to add with objects--a public language game--before they learn to add in their heads--a private language game. Rules, symbols, meaning, beliefs, and role models of language games are discussed. Philosophical themes of mental states are described, including clarity of description, the disunity thesis, parallelism, and the relationship between the mental and physical realms. A 28-item list of references is included. (Author/SLD)