This document describes curriculum and resources designed to foster and expand the philosophical thinking of elementary and middle school students. The booklet begins with excerpts from and a discussion of Matthew Lipman's novel "Harry Stottlemeier's Discovery," written to help elementary and middle school students discover both formal and informal rules of thought. Lipman and his associates established the Institute for the Advancement of Philosophy for Children (IAPC) at Montclair State College (New Jersey) in 1974. Subsequent chapters describe the successes and problems of the IAPC programs. The Institute continues to develop curricula designed to expand reasoning skills, beginning in early childhood education with reasoning in language comprehension and followed by reasoning skills in ethics, language arts, and social studies. It also conducts workshops to prepare teachers and teacher trainers in the use of the materials. Also discussed in the booklet are the philosophical foundations of philosophy for children and the significance of dialogue in teaching philosophy to children. The booklet concludes with an annotated listing of IAPC curriculum materials and a bibliography. (RM)