The nature and substance of relations among economics and other social sciences is complex. The relations vary in time. Since the late 1950, social sciences (law, management, political science, sociology, anthropology, psychology, economic history, geography) had been subjected to invasive inroads by economics. Economic theories and notions were used to explain phenomena that traditionally belonged to other disciplines, Starting from 1980. we observe a reversal - economics addresses other bodies of knowledge (e.g. experimental psychology, management or sociology) to supply it with data and the obtained results. In the article it is shown that this 'sui generis' economic imperialism had constituted an interdisciplinary extension of the methodological ideal of unification, which was present in the economic theory of main stream. We inspire to demonstrate that the reversal and the consecutive opening of economics towards other theories, that is, its partial departure from imperialism, had its roots in the internal theoretical and empirical problems encountered by economists. We formulate a methodological assessment of the process of reorientation of economics towards the cooperation with other sciences.