Michael Parsons reviewed the history of theories of artistic development and concluded that the linear models of Piaget and Lowenfeld cannot be defended in postmodern contexts. In its stead, he argued Parsons' change in children's art resembled a tree with many branches rather than a single path of growth, which was shaped by western, modern goals based upon a realistic depiction of the world. "Endpoint, Repertoires and Toolboxes. Development in Art as the Acquisitions of Tools." Tools were used as a metaphor for the diversity of conditions that influenced change in child art.