o suffered from a
dangerous gastric malady. He was successful in curing the Sultan, who
showed his gratitude by appointing Avicenna his vizier.

The affairs of State did not prevent Avicenna from carrying on his
studies, for during his stay at Hamadan he found time to commence his
exposition of the philosophy of Aristotle entitled the "Shifa" which he
undertook at the Sultan's request. At this time Avicenna presented the
rare spectacle of a philosopher discharging the functions of a
statesman, without injury to either statesmanship or philosophy. His
great physical energy enabled him to spend the day in the service of the
Sultan and a great part of the night in philosophical discussions with
his disciples. His writings, which date from this time, allow us to
judge with what success he pursued his philosophical studies, and we
have every reason to believe that he was equally successful in the
conduct of affairs, for, after the death of Shams-ed-Dawla, his son and
successor Taj-ed-Dawla requested him to retain the post of vizier.

Avicenna appreciated this testimony to his worth, but declined the offer
in order to devote himself to the completion of his great work, the
Shifa. But even in his studious retirement he was not out of reach of
political disturbance. Suspected of carrying on secret correspondence
with Ala-ed-Dawla, the governor of Ispahan, an enemy of Taj-ed-Dawla,
Avicenna was imprisoned in a neighbouring fortress. He would probably
have remained there a long time had not the fortune of war put
Ala-ed-Dawla in possession of Hamadan, Avicenna was liberated after an
imprisonment of four months. Despite this misadventure he succeeded
during his stay at Hamadan in completing the Shifa and several medical
treatises, besides, a little mystical allegory, "Hay ibn Yokdhan" ("The
living one, son of the Waking One"). This shows the mystical side of
Avicenna's philosophy, and we therefore subjoin an abridgment and
explanation of it.

"During my sojourn in a certain country, I used to make excursions with
my friends to pleasant spots in our vicinity. One day when strolling out
with them I met an old man who, in spite of his advanced age, seemed
brimful of juvenile ardour, being neither bent nor having white hairs.
We felt attracted by him and accosted him. After the usual salutations,
I opened the conversation by requesting him to inform us about himself,
his trade, name, family, and country. 'As to my name and family,'