Then he wrote the book entitled:

24.The Superessential Transcendent Principle Does Not Think. Which is the First Thinking Principle? And Which is the Second?[v. 6.]

He also wrote the following books:

25.Of Potentiality and Actualization.[ii. 5.]
26.Of the Impassibility of Incorporeal Entities.[iii. 6.]
27.Of the Soul, First Part.[iv. 3.]
28.Of the Soul, Second Part.[iv. 4.]
29.(Of the Soul, Third; or, How do We See?)[iv. 5.]
30.Of Contemplation.[iii. 8.]
31.Of Intelligible Beauty.[v. 8.]
32.The Intelligible Entities are not Outside of Intelligence. Of Intelligence and of Soul.[v. 5.]
33.Against the Gnostics.[ii. 9.]
34.Of Numbers.[vi. 6.]
35.Why do Distant Objects Seem Small?[ii. 8.]
36.Does Happiness (Consist in Duration?)[i. 5.]
37.Of the Mixture with Total Penetration.[ii. 7.]
38.Of the Multitude of Ideas; Of the Good.[vi. 7.]
39.Of the Will.[vi. 8.]
40.(Of the World).[ii. 1.]
41.Of Sensation, and of Memory.[iv. 6.]
42.Of the Kinds of Existence, First.[vi. 1.]
43.Of the Kinds of Existence, Second.[vi. 2.]
44.Of the Kinds of Existence, Third.[vi. 3.]
45.Of Eternity and Time.[iii. 7.]

Plotinos wrote these twenty-four books during the six years I spent with him; as subjects he would take the problems that happened to come up, and which we have indicated by the titles of these books. These twenty-four books, joined to the twenty-one Plotinos had written before I came to him, make forty-five.

VI. PLOTINOS'S BOOKS OF THE THIRD PERIOD
(THE EUSTOCHIAN PERIOD).

While I was in Sicily, where I went in the fifteenth year of the reign of Gallienus, he wrote five new books that he sent me:

46.Of Happiness.[i. 4.]
47.Of Providence, First.[iii. 2.]
48.Of Providence, Second.[iii. 3.]
49.Of the Hypostases that Act as Means of Knowledge, and of the Transcendent.[v. 3.]
50.Of Love.[iii. 5.]

These books he sent me in the last year of the reign of Claudius II, and at the beginning of the second.

Shortly before dying, he sent me the following four books: