The critical and creative thinking dispositions which are intrinsic to children's critical thought may reflect the standards of an adult culture which values verbalized thought over other kinds of human intelligence. Primary critical and creative thinking dispositions are those which help the child explore the world. These are biological processes that can be discerned as children discover the way things are as they play. Teachers can think of primary dispositions as functional components which underlie and impel children's need to discover. An inventory of such dispositions indicates that some, such as being open, resisting closure, tolerating frustration, taking risks, and controlling impulsivity, are associated with wonder. Other dispositions, including being imaginative, testing expectations, trying new things, practicing, are associated with exploration. In this paper, implications for classroom practice are discussed in terms of the ways in which teachers familiarize themselves with the primary dispositions as they are manifested in children, and ways of enhancing and assessing children's primary discovery dispositions. (RH)