This paper aims to critically reassess the quality and applicability of both concepts and models devised by Realist and Neorealist schools when studying Thucydides' historiographical work. Hence, the analysis will be focused on three main axes: the issue of human agency in his work, the historian's understanding and use of this notion, and how contemporary historians and Political scientists have downgraded or ignored such an important dimension when studying this work and its time. By way of specific case -studies, it is argued that three causes are to be pointed out as conducive to the so-called "pseudo-historical interpretations " of Thucydides and his Histories through misused methods originated in Political sciences: an exacerbated ontological pursue, documental as well as thematic athenocentrism, and disregarded archeo-epigraphical collaboration.