Many of the phenomena of object classification can be derived from a representation specifying a nonaccidental characterization of an object's parts (geons) and relations, termed a geon structural description (GSD). Such a representation: (a) enables the facile recognition of depth-rotated objects, even when they are novel, (b) provides the information that is employed not only to distinguish basic-level but also highly similar members of subordinate-level classes, and (c) enables mapping onto verbal and object-reasoning structures. Recent psychophysical and neural investigations of object recognition have provided additional support to this theory of object representation.