“As a financial scientist, Mann developed a sociology of taxation. His book on tax policy ideals shows that in different economic epochs there were quite different socio-political values and tax systems depending on them, which also sheds light on the necessary fundamental transformation of our tax system in the direction of high resource taxes and, among other things, a lower burden on the factor labor. Furthermore, three conceptual elements of his fiscal approach are extracted from his writings and his understanding of the relationship between tax theory and sociology is analyzed. Finally, the question is asked which of his writings, ideas, and concepts stand the test of time.” (H. Peukert)