the mastery of medical
science. His father was a native of Balkh, but removed from that city to
Bokhara; having displayed great abilities as a government tax collector
he was appointed to fill that office in a town called Kharmaithen, one
of the dependencies of Bokhara. Here Avicenna was born. At the age of
ten years he was a perfect master of the Koran, and had studied
arithmetic and algebra.

The philosopher An-Natili having visited them about that time,
Avicenna's father lodged him in his own house, and Avicenna studied
under him logic, Euclid and the Almagest (an astronomical treatise of
Ptolemy). He soon surpassed his master, and explained to him
difficulties and obscurities which the latter had not understood. On the
departure of An-Natili, Avicenna applied himself to the study of natural
philosophy, divinity, and other sciences. He then felt an inclination to
learn medicine, and studied medical works; he treated patients, not for
gain, but in order to increase his knowledge. When he was sixteen years
of age, physicians of the highest eminence came to him for instruction
and to learn from him those modes of treatment which he had discovered
by his practice. But the greater portion of his time was given to the
study of logic and philosophy. "When I was perplexed about any
question," he says in an autobiographical fragment, "I went to the
mosque and prayed God to resolve the difficulty. At night I returned
home; I lit the lamp, and set myself to read and write. When I felt
myself growing tired and sleepy I drank a glass of wine, which renewed
my energy, and then resumed reading. When finally I fell asleep I kept
dreaming of the problems which had exercised my waking thoughts, and as
a matter of fact often discovered the solution of them in my sleep."

When he came across the "Metaphysics" of Aristotle, that work in spite
of his acuteness seemed to present an insuperable difficulty. "I read
this book," he says, "but I did not understand it, and the purport of it
remained so obscure to me that though I read it forty times through and
could repeat it by heart, I was as far from understanding it as ever. In
despair, I said to myself, 'This book is quite incomprehensible.' One
day at the time of afternoon prayer I went to a bookseller's, and there
I met a friend who had a book in his hand, which he praised and showed
me. I looked at it in a listless way and handed it back, certain that it
was of no use to me. But he sa