Pursues William Kessen's analysis of psychologist Baldwin's 1905 paper by examining Baldwin's two proposed solutions to the mind-body problem: the materialist solution and the idealist solution. Demonstrates that Baldwin's ideas presaged those of developmental theorists and philosophers. Discusses Baldwin's proposal that current scientific ideas about mind and body are the product of historical distinctions developed in the history of Western culture and within individuals over the course of development. (Author/KB)