Suggesting that the concept of structure employed by political scientists in the analysis of belief systems is inadequate and misleading, the paper discusses Jean Piaget's concept of egocentrism as a theoretical alternative to belief systems analysis. The purpose of the paper is to provide political scientists with a short but comprehensive summary and introduction to Piaget's theory of cognitive development. The first part argues that current measures which, for example, analyze the degree to which respondents' beliefs conform to traditional ideologies (such as liberalism or conservatism) are measures of belief content rather than belief structure. This section demonstrates the weakness of constraint as a measure of structure. The second section, the major portion of the document, presents Piaget's concept of egocentrism. The section's emphasis is that the individual's belief structure is provided by the cognitive system of the mind. Topics include Piaget's "Genetic Epistemology" as the key to the structure of belief systems and egocentrism as the mainspring of genetic epistemology. Specifically, the discussion involves infantile, pre-operatory, concrete operational, and formal operational stages and cooperation as opposed to egocentrism. The final section offers both long-term and short-term methods for incorporating Piaget's theories into political science research. (KC)