In this paper, Plotinus' treatise On Dialectic I.3  is discussed. In the first part of the paper, I argue that for Plotinus the importance of dialectic stands in the method of division that enables one to grasp the ‘what it is’. I present and examine some passages which contain a description of dialectic and an account of its activity. I then look into the reasons why Plotinus affirms the superiority of dialectic, as he conceived it, over logic, as the Peripatetics and the Stoics conceived it. The second part of the paper explores the relation between dialectic and truth and that between dialectic and soul: in this discussion Plotinus offers some interesting and more original epistemological remarks.