Considering the characteristics of thought, Aristotle inclines in his On the Soul toward accepting the reality of a kind of intellect which is almost called "active intellect". His vague terminology and short statements concerning the ontological state of this intellect, however, has led to different, and in some cases, contradictory commentaries. In this paper, adopting a rigorous analytical approach to the issue along with appealing to Aristotle's own philosophical principles and texts, we propose a new interpretation according to which Aristotle believes in three kinds of intellect; an external active intellect (outside the human soul), an internal active intellect (inside the human soul) and a passive intellect so that the second and third are actually the same and consist in the actual and potential aspects of the single human intellect. As it is shown, this interpretation could be justified by several textual evidence and put an end to an old historical dispute.