There has been a considerable lack of taxonomic clarity in motivational research until today. Stressing the conceptual similarities of motives and values, an attempt is made to outline a general and parsimonious taxonomy for classifying motives by borrowing from Schwartz' (1992) values theory. First, a definition of motives is provided in the form of a so-called mapping sentence. This type of definition builds on Guttman's facet approach (cf. Borg & Shye, 1995) and lends itself to the specification and testing of hypotheses on the structure of motives. The tenability of these hypotheses is then investigated in a second step by analysing six multitrait-multimethod matrices of motives from five different studies, using nonmetric multidimensional scaling procedures. Besides the distinction of stable motivational domains, the impact of assessment procedures on the differentiation of motives in terms of the often used implicit-explicit discrimination (McClelland, 1985) is of focal interest in these analyses. All in all, the results speak for the usefulness of the structural approach chosen. Implications of these findings are discussed with respect to future research.