Methodology is not a "toolbox" of different methods from which the researcher selects some on the basis of personal or social preferences. If the Ganzheitspsychologie traditions of the last century have taught us anything, then it is the importance for scientific investigation to consider the developmental processes of the whole phenomena. We have taken a closer look at the fundamental ideology underlying qualitative and quantitative methodology in the context of development. For a thorough understanding, we must look critically at the meaning of "development," that is, the directional transformation of wholes. Through a historical overview of "lost" developmental perspectives, we discuss the possibility of a unification of qualitative and quantitative methods. We hope to make clear that methodology is an integrated structure of epistemological processes that can equally reveal and obscure the empirical reality in the knowledge construction process of social scientists. The coordination of the different perspectives depends on the interpretation of phenomena as well as the specific research questions. URN: urn:nbn:de:0114-fqs060189