Ibn Sina (or Abu Ali al-Husain ibn Abadllah and also known as Avicenna) of Hamadan, Persia (now Iran) believed himself to be a master of all the sciences, i.e., logic, the natural sciences and mathematics, and that all the gates of knowledge were opened to him (p 1 par 4). He is said to have mastered the Qu'ran at 10 and all the sciences at 18. His one all-consuming life obsession was learning and mastering knowledge: "I ... warned my father that I should not engage in any other occupation but learning." (p 1 par 2). The most important things in his life were, consequently, learning and reading on which it depended. A precocious learner at an early age, it naturally disturbed him badly when he could not comprehend the Greek philosopher Aristotle's "Metaphysics." When he finally did after reading Abu Nasr al-Farabi's "On the Objects of Metaphysics" (which he initially rejected and bought only out of pity for the seller), he was so overjoyed that he gave alms in gratitude to God.

Al-Ghazali (or AbuHamid Muhammad al-Ghazali) of Tus, Khurasan, on the other hand, believes that he possessed the instinct to know the sciences and the religious systems without error:

"To thirst after a comprehension of things as they really are was my habit and custom from a very early age. It was instinctive with me, a part of my God-given nature, a matter of temperament and not of my choice or contriving." (p 2 par 3)

Like Ibn Sina, Al-Ghazali was totally and fervently devoted to discovering and acquiring true knowledge as the most important thing in life for him:

"I have ever recklessly launched out into the midst of these ocean depths, I have ever bravely embarked on this open sea, throwing aside all craven caution; I have poked into every dark recess, I have made an assault on every problem, I have plunged into every abyss, I have scrutinized the creed of every sect, I have tried to lay bare the inmost doctrines of every community. all this have I done that I might distinguish between true and false, between sound tradition and heretical innovation." (p 2 par 2).

Both were, therefore, motivated by the same thing. Ibn Sina's goals were, however, chiefly intellectual in nature. He claimed to have learned and mastered not only the said sciences but also philology itself (the love of learning) when once insulted and challenged. He likewise made it his supreme business to solve every problem that came his way with every means and time in his disposal until he found the precise solution. In the pursuit of every knowledge and every solution to every problem, Ibn Sina studied all day and all night and kept himself awake by drinking wine in order to regain physical and mental strength and alertness. He, furthermore, prayed at the Mosque for the solution or answer for each problem. Or extended his problem-solving rage to his sleep so that the solution would be yielded to him while he slept.

Al-Ghazali dedicated himself entirely to the same pursuit, specifically:

"...to show the aims and inmost nature of the sciences and the depths of the religious systems, to extricate the truth from the confusion of contending sects; to distinguish the different ways and methods; to climb from a naive or second-hand knowledge to direct vision; to describe the profits he would derive from the science of theology and what he approved or disapproved in the Sufi's way of life." (p 1 par 1).

His ultimate goal was clearly to know the essentials of every belief (p 1 par 1).He sought error-free knowledge which was the only kind of knowledge that was certain.

He held that a learner must first become acquainted with and understand the depths of a system before gaining knowledge about it. He also wanted to show the supporters of Authoritative Instruction that nothing protected them from the danger and darkness of mere opinion:

"All they amounted to was a deception of the ordinary man and the weak intellect by proving the need for an instructor ... If he were to attempt to proceed farther, his shameful condition would be revealed and he would be unable to resolve the least of this problems -- that he would be unable even to understand them, far less to answer them.: (p 18 par 1).

In the pursuit of their common obsession, they certainly met with huge crises. Ibn Sina was restless day and night when he could not understand Aristotle's...

When his father died, he had to be employed at the Sultan's office. At that time, he had to move from place to place, and hoped to see Amir Qabus, but did not, because the object of his search was taken prisoner and later died.
Ibn Sina later became close to Amir and, on their way to make war against Annaz, they were defeated and Ibn Sina was returned to Hamadan. When he was eventually made the vizier, the army rose against him, took his belongings, imprisoned and almost killed him. He hid at the house of Shaykh Abu Sa'd ibn Dakhduk for 40 days and was saved only by a turn of events.

He was treating the Amir of his acute colic which was the result of the latter's irregular personal habits and refusal to follow Ibn Sina's instructions. The Amir later died of the colic. Ibn Sina was offered the position of vizier but refused it and instead went into hiding, this time, at the house of Abu Ghalib, the druggist. At that time, he was secretly communicating with Ala al-Dawla while he completed the 8 folios on the logic of healing from memory. But an enemy betrayed him concerning his secret communication with Ala al-Dawla and he was imprisoned at the Fardajan fortress for four months. Disguised as Sufi monks, he and a small group went in stealth to Ishafan and suffered a lot on the way.

At a latter time, Ibn Sina was severely insulted by Abu Mansur al-Jabban about his neophyte views on philology which he had yet to learn well and master. This was one more crisis he faced.

And towards the end of his life, he himself was afflicted with colic during a clash between his friend Ala al-Dawla and Tash Farash. In the midst of the battle, his condition was so severe that had to administer enema on himself eight times daily, to the point that his intestines became thin and ulcerated. As a frantic measure, his attending physician introduced 5 dirhams of celery seed into the solution which made the colic worse. Opium was also mixed into his enema to alleviate the pain. For a while, Ibn Sina's treatment allowed him to walk. He became a regular member of the court of Ala al-Dawla, but Ibn Sina engaged in intense sexual activity despite his colicky condition. This resulted in several extremely and fatal relapses. During the court's march to Hamadan, led by Ala al-Dawla, his self-treatments began to fail and gave them up. Before he died, he said:

"The governor who used to govern my body is incapable of governing me any more. So it is no use trying to cure my sickness." (p 7)

The chief crises confronted by Al-Ghazali, unlike Ibn Sina's, were intellectual and spiritual or religious in nature. First, he despaired over his inability to find infallible knowledge, except in the case of sense perception and necessary truths. In time, he also subjected sense perception and these necessary truths into reflection and began doubting them as well. He soon performed experiments that led him to discover that only intellectual truths (first principles) were, in fact, reliable. It was an unhealthy and difficult state for him which pushed him into becoming a skeptic for two months. Both his cure and the restoring of his trust in intellectual truths had to be worked directly by God..

He continued his search. This time, he undertook a diligent study of philosophy, but discovered afterwards that the science did not yield infallible knowledge, either. It did not solve his problems. He went on and more feverishly to examine Sufism or mysticism. In the process, he made a self-discovery which told him that he was engrossed in several studies of little value and without profit to his salvation. Upon earnest examination of his motives, he realized that he was motivated: "not (by a ) consecration to God, but only by the desire for honor and reputation." (p 18). He suffered the painful threat of damnation to eternal fire if he was not immediately converted. Yet he remained in an uncertain state. Opposing forced tempted him to take this or that way. It was a gripping collision between earthly passions and religious aspirations for six months until he gave himself up to God at the end. But the evil opponent did not just give him up: al-Ghazali turned dumb. He responded to the spiritual constraint desperately and violently. His stomach grew weak and he lost all appetite. Doctors diagnosed…