The combination of explanations according to the statement view and the non-statement view on the basis of an individual system as a model for the research foundation in psychology

It is shown how the crisis of confidence in psychology can be overcome by a form of theory development. Theories are evaluated on the basis of the classical causae of Aristotle (formalis, materialis, efficiens, finalis). According to this, psychological theories should provide answers to three questions: what, how and why. These three questions can only be answered by supplementing the statement view with the non-statement view. This leads to the necessity of introducing models that hold target parameters and also incorporate systemic references into theories. Such an extension requires a complex examination of the quality of a basic model. A first assessment has been made by embedding central concepts from social psychology into such a model (Witte, 2024). The second important step for such an evaluation is to draw a direct connection between empirical studies, their quantitative reconstruction, and their explanation in the sense of a causa finalis and the selected model. In terms of content, 13 different areas are selected and explained with the help of the model, ranging from crowding to justice, psychophysics, and heuristics. This increases systematicity as an essential criterion of science and demonstrates a possibility for theoretical cooperation in research.