They hope to get the credit of minute and exact identification by setting up a plurality of intellectual Essences; but in reality this multiplication lowers the Intellectual Nature to the level of the Sense-Kind: their true course is to seek to reduce number to the least possible in the Supreme, simply referring all things to the Second Hypostasis – which is all that exists as it is Primal Intellect and Reality and is the only thing that is good except only for the first Nature – and to recognize Soul as the third Principle, accounting for the difference among souls merely by diversity of experience and character. Instead of insulting those venerable teachers they should receive their doctrine with the respect due to the older thought and honour all that noble system – an IMMORTAL SOUL, an Intellectual and Intelligible Realm, the Supreme God, the Soul’s need of emancipation from all intercourse with the body, the fact of separation from it, the escape from the world of process to the world of essential-being. These doctrines, all emphatically asserted by Plato, they do well to adopt: where they differ, they are at full liberty to speak their minds, but not to procure assent for their own theories by flaying and flouting the Greeks: where they have a divergent theory to maintain they must establish it by its own merits, declaring their own opinions with courtesy and with philosophical method and stating the controverted opinion fairly; they must point their minds towards the truth and not hunt fame by insult, reviling and seeking in their own persons to replace men honoured by the fine intelligences of ages past. Enneads II,9,6
(18) But how does the soul enter into body from the aloofness of the Intellectual? There is the Intellectual-Principle which remains among the intellectual beings, living the purely intellective life; and this, knowing no impulse or appetite, is for ever stationary in that Realm. But immediately following upon it, there is that which has acquired appetite and, by this accruement, has already taken a great step outward; it has the desire of elaborating order on the model of what it has seen in the Intellectual-Principle: pregnant by those Beings, and in pain to the birth, it is eager to make, to create. In this new zest it strains towards the realm of sense: thus, while this primal soul in union with the Soul of the All transcends the sphere administered, it is inevitably turned outward, and has added the universe to its concern: yet in choosing to administer the partial and exiling itself to enter the place in which it finds its appropriate task, it still is not wholly and exclusively held by body: it is still in possession of the unembodied; and the Intellectual-Principle in it remains immune. As a whole it is partly in body, partly outside: it has plunged from among the primals and entered this sphere of tertiaries: the process has been an activity of the Intellectual-Principle, which thus, while itself remaining in its identity, operates throughout the soul to flood the universe with beauty and penetrant order – immortal mind, eternal in its unfailing energy, acting through IMMORTAL SOUL. Enneads IV,7,13