When we try to study the periods in Plotinos's thought, as shown in his books, we are met with great difficulties, which are chiefly due to Porphyry. Exactly following the contemporary methods of the compilers of the Bible, he undiscerningly confused the writings of the various periods, so as to make up an anthology, grouped by six groups of nine books each, according to subjects, consisting first of ethical disquisitions; second, of physical questions; third, of cosmic considerations; fourth, of psychological discussions; fifth, of transcendental lucubrations; and sixth, of metaphysics and theology.[440] As the reader might guess from the oversymmetrical grouping, and this pretty classification, the apparent order is only illusory, as he may have concluded from the fact that the discussions of matter analyzed above are scattered throughout the whole range of this anthology. The result of this Procrustean arrangement was the same as with the Bible: a confusion of mosaic, out of which pretty nearly anything could be proved, and into which almost everything has been read. Compare the outlines of the doctrines of Plotinos by Ritter, Zeller, Ueberweg, Chaignet, Mead, Guthrie, and Drews, and it will be seen that there is very little agreement between them, while none of them allow for the difference between the various parts of the Enneads. How fearful the confusion is, will best be realized from the following two tables, made up from the indications given in Porphyry's Life of Plotinos. Porphyry gives three lists of the works of the various periods. Identifying these in the present Ennead arrangement, they are to be found as follows: The works of the Amelian period are now i. 6; iv. 7; iii. 1; iv. 2; v. 9; iv. 8; iv. 4; iv. 9; vi. 9; v. 1; v. 2; ii. 4; iii. 9; ii. 2; iii. 4; i. 9; ii. 6; v. 7; i. 2; i. 3; i. 8. The works of the Porphyrian period are now vi. 5, 6; v. 6; ii. 5; iii. 6; iv. 3-5; iii. 8; v. 8; v. 5; ii. 9; vi. 6; ii. 8; i. 5; ii. 7; vi. 7; vi. 8; ii. 1; iv. 6; vi. 1-3; iii. 7. The works of the latest or Eustochian period are: i. 4; iii. 2, 3; v. 3; iii. 5; i. 8; ii. 3; i. 1; i. 7. (For Eustochius, see Scholion to Enn. iv. 4.29, ii. 7.86, Creuz. 1, 301 Kirchhof.) A more convenient table will be the converse arrangement. Following the present normal order of the books in Enneads, we will describe its period by a letter, referring to the Amelian period by A, to the Porphyrian by P, and the Eustochian by E. I: EAAEPAEAA. II: PAEAPAPPP. III: AEEAEAPPA. IV: AAPPPPAAA. V: AAEAPPAPA. VI: PPPPPPPPA. This artificial arrangement into Enneads should therefore be abandoned, and in a new English translation that the writer has in mind, the books would appear in the order of their periods, while an index would allow easy reference by the old numbers. Then only will we be able to study the successive changes of Plotinos's thought, in their normal mutual relation; and it is not difficult to prophesy that important results would follow.