Another pupil of Ammonius was Cassius Longinus, born in 213 at Emessa (Homs) in Asia Minor.  Later he taught Platonism for thirty years at Athens; then in the two-sixties went east to the court of Zenobia at Palmyra,—­whose brilliant empire, though it fell before the Illyrian Aurelian, was a sign in its time that the Crest-Wave had come back to West Asia.  Longinus became her chief counselor; it was by his advice that she resisted Aurelian;—­who pardoned the Arab queen, and, after she had paraded Rome in his triumph, became very good friends with her; but condemned her counselor to death.  But Longinus I think had failed to follow in the paths laid down for him by his Teacher:  we find him in disagreement with that Teacher’s successor.

Who was Plotinus, born of Roman parents at Lycopolis in Egypt.  It is from his writings we get the best account of Ammonius’ doctrine.  He was with the latter until 243; then joined Gordian III’s expedition against Persia, with a view to studying Persian and Indian philosophies at their source.  But Gordian was assassinated; and Plotinus, after a stay at Antioch, made his way to Rome and opened a school there.  This was in the so-called Age of the Thirty Tyrants, when the central government was at its weakest.  Gallienus was emperor in Rome, and every province had an emperorlet of its own;—­it was before the Illyrian peasant-soldiers had set affairs on their feet again.  A lazy erratic creature, this Gallienus; says Gibbon:  “In every art that he attempted his lively genius enable him to succeed; and, as his genius was destitute of judgement, he attempted every art, except the important ones of war and government.  He was master of several curious but useless sciences, a ready orator, an elegant poet, a skilful gardener, an excellent cook, and a most contemptible prince.”  Yet he had a curious higher side to his nature, wherewith he might have done much for humanity,—­if he had ever bothered to bring it to the fore.  He, and his wife, were deeply interested in the teachings of Plotinus.  Such a man may sometimes be ‘run,’ and made the instrument of great accomplishment:  a morass through which here and there are solid footholds; if you can find them, you may reach firm ground, but you must walk infinitely carefully.  It is the old tale of the Prince with the dual nature, and the Initiate who tries to use him for the saving of the world,—­and fails.

Plotinus knew what he was about.  Was it last week we were talking of the endless need of the ages:  a stronghold of the Gods to be established in this world, whence they might conduct their cyclic raidings?  What had Pythagoras tried to do in his day?—­Found a Center of Learning in the West, in which the Laws of Life, physical, mental, moral, and spiritual, should be taught.  He did found it,—­at Croton; but Croton was destroyed, and all the history of the next seven centuries suffered from the destruction.  Then—­it was seven centuries after his death,—­