Abstract: This book focuses on Plotinus' notion of Intellect. Intellect comes second in Plotinus' hierarchical model of reality, after the One, which is an unknowable first cause of everything. Intellect is also the sphere of being, the Platonic Ideas, which exist as its thoughts. Plotinus' doctrine of Intellect raises a host of questions that the book seeks to answer: Intellect's thought is described as an attempt to grasp the One and at the same time as self-thought. How are these two claims related? How are they compatible? What lies in Plotinus' insistence that Intellect's thought is a thought of itself? The minimal requirements thought must satisfy according to Plotinus is that it must involve a distinction between thinker and object of thought, and the object itself must be varied. How are these two claims which amount to holding that Intellect is plural in two different ways related? What is the relation between Intellect as a thinker and Intellect as an object of thought? Plotinus' position here seems to amount to a form of idealism, a claim that is explored in the book. As opposed to ordinary human discursive thinking, Intellect's thought is all-at-once, timeless, truthful, and a direct intuition into ‘the things themselves’; it is presumably not even propositional. This strong notion of non-discursive thought is discussed and explained as well as Plotinus' claim that this must be the primary form of thought. The main conclusion of the book is that though clearly dependent on the Platonic-Aristotelian tradition, Plotinus' theory of Intellect contains very significant innovations.

Keywords: activity, Aristotle, being, discursive, idealism, limits of thought, non-discursive, Plato, self-thinking, self-awareness, the One, thought