As a leading centre of Islamic learning, Nishapur also attracted eminent Sufi personalities who lived there and imparted knowledge of Islamic esoteric (batin) sciences to their followers and sympathisers. Al-Ghazali also attended these Sufi lodges (zawiyyah) and received training in the theoretical and practical dimensions of Sufism under the able guidance of Abu Ali Fadl ibn Muhammad ibn Ali al-Farmadhi, who was a widely respected Sufi personality of Nishapur and a pupil of the renowned al-Qushairi. In 1085 al-Juwayni died and al-Ghazali was asked to become professor of Islamic thought at the Nizamiyyah College in Baghdad by none other than Nizam al-Mulk himself, the great Seljuk Prime Minister and founder of the Nizamiyyah College. At the age of around thirty-four, he became the youngest professor at Nizamiyyah. This was an extraordinary honour for young al-Ghazali since the Nizamiyyah College of Baghdad was the Oxford or Harvard of its time. As soon as al-Ghazali started teaching fiqh, kalam and hadith at Nizamiyyah, his name and fame began to spread across the Islamic dominion and Nizam al-Mulk became his patron, regularly consulting him on all the important religious and political issues of the day. Al-Ghazali’s daily lectures at Nizamiyyah became so popular that up to three hundred students came to listen to him at a time. However, just when he thought he had achieved all that was possible for someone so young to achieve, he suddenly found himself stranded in the middle of an intellectual crisis.
This crisis made al-Ghazali restless. Being inherently inquisitive, and sceptical of received wisdom, he thrived in the lion’s den. He questioned everything and, in the process, left no stone unturned. He was profoundly disturbed by the apparent conflict between the views of the rationalists, who argued that human reason (aql) was superior to revelation (wahy), and the traditionalists who considered Divine revelation to be infallible and, therefore, more authoritative in comparison with fallible human reason. Although al-Ghazali was not a philosopher per se, he had studied philosophical thought during his period with al-Juwayni. This enabled him to understand and evaluate the various strands of philosophical and theological thought which prevailed in the Muslim world at the time. His observations disturbed him profoundly and made him very restless. He discovered that a huge array of religious sects and groups had emerged which also espoused their own sets of doctrines, beliefs and concepts which, he felt, were not only heretical in nature, but also directly contradicted traditional Islamic teachings and practices. How was he to determine which group was right and which one was wrong in the face of these diverse claims and counter-claims?
This prompted al-Ghazali to resign from Nizamiyyah College and study all the prominent religious sects and groups. In the course of his studies, he became aware of the limitations of existentialism and rationalism. He found them to be unreliable categories for reaching the Truth. The more al-Ghazali questioned the more he doubted the very foundation of knowledge. Thus, for a period, he became a fully-fledged sceptic, living in a state of doubt and depression. However, it should be noted here that the Ghazzalian doubt was not the opposite of faith; rather it was an integral part of faith because his scepticism did not lead him to doubt the existence of God. Yet, it is true that he found himself stranded in an intellectual no-man’s land and that he found no comfort in rational arguments or in logical proofs as a means of solving his predicament. That was when he claimed to have been saved by the ray of Divine light (nur) which entered his heart and delivered him from his intellectual dilemma. Al-Ghazali considered this to be a gift from God Who had chosen to guide him to the straight path (sirat al-mustaqim). This brought much needed peace and solace to his tortured mind and body as he affirmed the superiority of prophetic revelation and intellectual intuition over human rationality. At peace with himself, and reassured of the authenticity of his approach to Islam, he now continued his study of all the religious sects and groups in order to discover the truth for himself.
He began by studying and analysing the works of the philosophers and theologians. He divided seekers-after-knowledge into four different categories, namely the scholastic theologians (mutakallimun), the philosophers (falasifah), the doctrinaires (ta’limiyya or Ta’limites), and the Sufis (Islamic mystics). During this period he delved deep into theology, natural philosophy, religious heresy and the supra-rational world of mysticism, until he attained a thorough understanding of these subjects. Al-Ghazali set himself a formidable task but he was determined to complete his mission. Having already studied scholastic theology under al-Juwayni’s tutelage at Nizamiyyah College, he was thoroughly familiar with this subject. Nevertheless, he undertook a fresh analysis of its basic principles and logical parameters, only to discover that it had major shortcomings. The theologians’ prodigious ability to theorise, debate and argue their case aside, al-Ghazali found no common ground on which all theologians could agree. He argued, therefore, that scholastic theology would be of no value to anyone unless they believed in the indispensability of human reason. During this period he authored a number of books on theology, before pursuing research in philosophy.
For the next three years (that is, from 1091 to 1094), he conducted a thorough study of falsafah (or Islamic philosophy). Through extensive study and research he became fully acquainted with the works of the philosophers including those of great Muslim philosophers like al-Farabi and Ibn Sina. He considered their ideas and thoughts to be confused and misguided. The outcome of his study of philosophy was Maqasid al-Falasifah (The Intentions of the Philosophers) which al-Ghazali intended to serve as an introduction to his famous Tahafut al-Falasifah (The Refutation of the Philosophers). In this book, he systematically analysed and repudiated Peripatetic (mashsha’iyyah) philosophy as propounded by al-Farabi and Ibn Sina. In the preface to this book, he explained that his intention was to free Islamic thought from the stranglehold of Greek philosophy. By refuting the ‘errors and heresies’ of the philosophers, he hoped to safeguard the masses from doubt and confusion. Al-Ghazali’s attack on Peripatetic philosophy proved so successful that Greek philosophical thought never managed to re-emerge in the Muslim world in a significant way after that. He single-handedly accomplished a feat which even a group of gifted intellectuals would have struggled to achieve. By all accounts, this was a truly remarkable achievement. Astonishingly, al-Ghazali was only thirty-six when he authored his hugely influential Tahafut.
After philosophy, al-Ghazali turned his attention to a doctrinare sect called the Ta’limites. This group believed that an ‘infallible teacher’ would one day appear and restore peace and order throughout the land. Al-Ghazali studied the beliefs and doctrines of this sect, and refuted their claims in his books. Fada’ih al-Batiniyya wa Fada’il al-Mustazhiriyya (The Infamies of the Batinites and the Virtue of the Mustazhrites) was one such work, and it sparked off a huge debate between al-Ghazali and the supporters of this sect. After this, he immersed himself in the ocean of Sufi thought and practices. Following a thorough study of the works of prominent Sufis like Abu Talib al-Makki, Harith al-Muhasibi, Abul Qasim al-Junayd al-Baghdadi, Abu Bakr al-Shibli and Abu Yazid al-Bistami, al-Ghazali realised that ‘empirical’ – as opposed to ‘theoretical’ – knowledge was the foundation of Sufism. This prompted him to renounce all worldly pleasures and plunge himself whole-heartedly into the vast ocean of Sufism, only to experience yet another crisis. This time he suffered a serious nervous breakdown which badly affected his physical health, and he also developed speech problems. According to al-Ghazali, his situation did not improve until God again delivered him from his predicament by illuminating his heart with the spirit of truth. Now he was able to differentiate between ‘theoretical’ knowledge and ‘experiential’ knowledge. Hereafter, he devoted all his time and energy to seeking experiential knowledge in order to move closer to Divine proximity like the Sufis. He felt that endless theological debates, philosophical hair-splitting and heretical interpretations of Islamic beliefs and principles were unlikely