Routledge is now re-issuing this prestigious series of 204 volumes originally published between 1910 and 1965. The titles include works by key figures such asC.G. Jung, Sigmund Freud, Jean Piaget, Otto Rank, James Hillman, Erich Fromm, Karen Horney and Susan Isaacs. Each volume is available on its own, as part of a themed mini-set, or as part of a specially-priced 204-volume set. A brochure listing each title in the "International Library of Psychology" series is available upon request.

First published in 1999. Routledge is an imprint of Taylor & Francis, an informa company.

This volume from Piaget s laboratory in Geneva deals primarily with the development of notions of measurement and geometrical concepts like coordinates, angles, and areas. It is a companion piece to The Child s Conception of Space."