the diversity of things is addressed to what is peculiar to each order of intellect, their unity can be taken up only by what is common to all orders of intellect. Unity is thus the object of philosophical pursuit, inasmuch as it is the truth for all, in other words, the absolutely true. Fifthly, But what is this unity? The Alexandrian philosophy is driven in upon the answer that thought is the unity of the universe. Hence the knowledge of self, the thought of thought the reflection of reason upon itself, is inculcated by Plotinus as the highest duty, and as the noblest source of purification and enlightenment. This is the sum and substance of his teaching, in so far as it can be intelligibly reported.
7. To the system thus concisely exhibited, some explanation must be appended, showing, first, the grounds on which Plotinus and the Platonists generally refused to acknowledge the material world as the absolutely real; secondly, in what respect the Alexandrian philosophy differs from antecedent systems; and, thirdly, how Plotinus was led to lay down thought as the absolutely real, and as constituting the unity in all things. A few words on each of these points.
8. I.—The consideration that the truth which philosophy aims at is the truth for all, disposed at once of the claim of the material world to be regarded as absolutely true; for matter is not a truth for all intellect, but only for intellect furnished with such
