The philosophy of Plotinus is an account of an ordered structure of living reality, which proceeds eternally from its transcendent First Principle, the One or Good, and descends in an unbroken succession of stages from the Divine Intellect and the Forms therein through Soul with its various levels of experience and activity to the last and lowest realities, the forms of bodies: and it is also a showing of the way by which the soul of man which belongs to, can experience and be active on every level of being, is able, if it will, to ascend by a progressive purification and simplification to that union with the Good which alone can satisfy it. There are two movements in Plotinus’s universe, one of outgoing from unity to an ever-increasing multiplicity and the other of return to unity and unification: and, related to his conception of these two movements but not entirely corresponding to them, there is a duality and tension in his own thought. On one side there is the attempt to give a completely objective and accurate account of the whole of reality, based on metaphysical reflection, with plenty of hard thinking and argument, and owing a good deal to preceding philosophies, above all of course to the Platonic school tradition: and on the other there is the faithful transcription of his own interior spiritual experience of ascent to and union with the One (NA: These two aspects of Plotinus’s thought are labelled by modern German-speaking scholars ‘gegenständlich’ and ‘aktuell’, terms first used in this connexion by P. O. Kristeller in Der Begriff der Seele in der Ethik des Plotins (1929)). If we are to arrive at a true appreciation of Plotinus’s thought we must not separate the two sides too sharply. It is, of course, when he speaks of the return to unity, the ascent of the soul to the One, that he draws most on his own experience; and when he is describing the eternal pattern of reality as it spreads out in increasing multiplicity on its successive levels in the movement of descent his thought takes on more the character of objective metaphysical reflection, and he argues more and appeals less to experience; it is on this side of his thought, too, that the influence of the school tradition is most marked. But it is quite impossible to separate his metaphysics neatly from his mysticism. His whole description of the nature of reality is coloured and brought to life by his own spiritual experience: and his account of that experience, of the ascent of the soul and the mystical union, is kept firmly in accordance with the structure of his metaphysics. Of course the three great Hypostases, the One, Nous or the Divine Intellect, and Soul look rather different when seen from different points of view. And Plotinus does not, any more than any other great philosopher, attain complete coherence and consistency in his thought. To many questions he gives answers which vary, though always within well-defined limits, according to the point of view. There is a notable fluctuation in his thought about the precise degree of goodness or badness to be attributed to the body, and more generally in the evaluation of the descent into multiplicity, which appears both as a good and necessary self-expansion and as evil and a fall due to self-will and self-assertion. This fluctuation may perhaps be regarded to some extent as due to a tension between the metaphysical and mystical sides of his thought, though it also derives, as Plotinus was very well aware, from a similar tension in the thought of Plato: and in his effort to present Plato’s thought as perfectly reasonable and consistent he tries hard, if not altogether successfully, to resolve it (NA: cp. IV. 8. 5 (F (c), p. 133), in these selections). And there are other fluctuations and tensions besides this major one. There are elements in his experience which do not fit into his system, elements in the tradition he inherited which are not fully assimilated, and lines of thought suggested which if they had been followed up might have led to a radical revision of his philosophy. But his thought cannot be simply resolved into a mere jumble of conflicting elements. He is at once metaphysician and mystic, a hard and honest thinker who enjoyed intense spiritual experience and could describe it in the language of a great poet, an ascetic who affirmed the goodness of the world of the senses, a traditionalist who could think for himself and encouraged free discussion in others.