Since the doctrine of Ammonius is unknown to us, we have no means of gauging the extent to which Plotinus depends on him: but probably we shall not be far wrong if we attribute to his influence the peculiar sense of reality, the deep spiritual inwardness, colour and life, with which his great pupil invests the dogmas of Platonism. The main elements of the Plotinian philosophy, however, are undoubtedly Platonic. The Divine Triad, the precession of spirit and its return to its origin, the unreal world of sense, the universal soul, the “real” or intelligible world of the Ideas—these and other ingredients of his system are a part of the common stock of Platonism. His originality and his attraction consist in the use which he makes of them, the colour and atmosphere with which they are endowed. That which is truly his own is the living vision which creates from these formulæ a vivid world both actual and poetic, answering with fresh revelations of reality the widening demands and apprehensions of the human soul. This spiritual world is not merely arrived at by a dialectic process. It is the world of his own intense experience from which he speaks to us; using his texts, as Christian mystics have often used the Bible, to support doctrines inspired by his personal vision of truth. In spite of his passion for exactitude, the sharpness and detail of his universe, he is thrown back, again and again, on the methods of symbol and poetry. We must always be ready to look past his formal words to the felt reality which he is struggling to impart; a reality which is beyond the grasp of reason, and can only be apprehended by the faculty which he calls spiritual intuition. To this we owe the richness and suppleness of his system, the absence of watertight compartments, the intimate relation with life. Whilst many philosophers have spent their powers on proving the necessary existence of an unglimpsed universe which shall satisfy the cravings of the mind, Plotinus spent his in making a map, based on his own adventures in “that country which is no mere vision, but a home;” and his apparently rigid contours and gradients are attempts to tell at least the characteristics of a living land. Though the Enneads are a storehouse of profound and subtle thought, the main principles on which their philosophy is based are simple, and can be expressed briefly. All things, according to Plotinus, have come forth from the Absolute Godhead or One, and only fulfil their destiny when they return to their origin. The real life of the universe consists in this flux and reflux: the outflow and self-expression of spirit in matter, the “conversion” or return of spirit to the One. With the rest of the Neoplatonists, he conceives of the Universe as an emanation, eternally poured forth from this One, and diminishing in reality and splendour the further it is removed from its source. The general position is somewhat like that given by Dante in the opening of the _Paradiso_: