Tiedeman (1919-2004) designed the blueprint for equipping and building career construction theory. After making significant contributions to the statistical analysis of occupational behavior, he shifted to a constructivist epistemology for comprehending careers as the imposition of direction on vocational behavior. The cornerstones of his theoretical edifice unite the concepts that career emerges from self-organization, purposeful action bridges discontinuity, and decisions evolve through differentiation and integration. His counseling methods help clients reorganize self to better pursue purpose at work and in leisure. Tiedeman's model and methods remain instructive and inspiring to the contemporary theory and practice of career construction.
When individuals of deep scholarship and intellectual daring lunge ahead of the learned community whom they are addressing, they may not receive the honor that they deserve. Instead, they may blend undistinguished into the scholarly landscape and somehow become taken for granted. Something like this has happened to the scholarly contributions of David Valentine Tiedeman (1919-2004). Being the first psychologist to systematically apply constructivist epistemology to the comprehension of careers, Tiedeman broke with intellectual traditions to lead the counseling profession in a new direction. As he cleared a path into the future, he identified what was to be avoided and articulated what was to be done. When others lagged behind, he moved forward by himself. Tiedeman's path has now moved through the progression identified by the German philosopher Arthur Schopenhauer (1788-1860): "All truth passes through three stages. First, it is ridiculed. second, it is violently opposed. Third, it is accepted as being self-evident." Such has been tile course followed by the seminal contributions of Professor Tiedeman, the prime engineer of career construction theory.
In this article, I outline three of Tiedeman's most profound truths: career emerges from self-organization, purposeful action bridges discontinuity, and decisions evolve through differentiation and integration. Before doing so, I describe the prehistory of Tiedeman's (1964) constructivist model of careers, namely, his contributions to the normal science of vocational psychology as represented by the individual differences tradition of personality types (Holland, 1959) and the developmental tradition of vocational tasks (Super, 1957). Kuhn (2000} described normal science as the routine work of individuals conducting programmatic research within an established model. This methodical work slowly elaborates the theoretical model by making incremental additions. The work does not challenge the underlying assumptions of the model, as Tiedeman would eventually do, but I am getting ahead of the story of his beginning as a positivist and becoming a constructivist.
Beginning as a Posirivist
Before initiating a paradigm shift in vocational psychology, Tiedeman earned a BA in psychology at Union College (1941). While there, he studied with Ernest M. Ligon, leader of the Character Research Project and author of an innovative student workbook titled A Purpose for Tour Life (Ligon, 1972). Ligon (1956) taught Tiedeman that ""science is seeing something in the fliture, not proving something to be true" (p. 38). Following the completion of his studies at Union College, Tiedeman moved to the University of Rochester from which in 1943 he earned an MA in psychology. Being interested both in engineering and in psychology, Tiedeman believed that he could balance these two interests by studying statistics. So he then moved to Harvard University from which in 1948 he earned an EdM and in 1949 an EdD, both in educational measurement. His dissertation, sponsored by the prominent statistician Phillip Justin Rulon, was tided "A Classification of Elementary College American History, Mathematics, and Physics Courses by an Analysis of the Prerequisite Knowledge Necessary" (Tiedeman, 1949). …