structural:summarization, stylistic:tone, information:filtering
Reception of work

According to William Montgomery Watt, al-Ghazali was considered to be the mujaddid ("Reviver") of his age. Many, perhaps most, later Muslims concurred and, according to Watt, some have even considered him to be the greatest Muslim after Muhammad.

As an example, the Islamic scholar al-Safadi stated:

Muhammad ibn Muhammad ibn Muhammad ibn Ahmad, the Proof of Islam, Ornament of the Faith, Abu Hamid al-Tusi (al-Ghazali) the Shafi'ite jurist, was in his later years without rival.

and the jurist, al-Yafi'i stated:

He was called The Proof of Islam and undoubtedly was worthy of the name, absolutely trustworthy (in respect of the Faith) How many an epitome (has he given) us setting forth the basic principles of religion: how much that was repetitive has he summarised, and epitomised what was lengthy. How many a simple explanation has he given us of what was hard to fathom, with brief elucidation and clear solution of knotty problems. He used moderation, being quiet but decisive in silencing an adversary, though his words were like a sharp sword-thrust in refuting a slanderer and protecting the high-road of guidance.

The Shafi'i jurist al-Subki stated:

"If there had been a prophet after Muhammad, al-Ghazali would have been the man".

Also a widely considered Sunni scholar, al-Dhahabi, in his praise of al-Ghazali wrote: "Al-Ghazzaali, the imaam and shaykh, the prominent scholar, Hujjat al-Islam, the wonder of his time, Zayn al-Deen Abu Haamid Muhammad ibn Muhammad ibn Muhammad ibn Ahmad al-Toosi al-Shaafa'i al-Ghazzaali, the author of many books and one possessed of utter intelligence. He studied fiqh in his own town, then he moved to Nisapur in the company of a group of students. He stayed with the Imaam al-Haramayn and gained a deep knowledge of fiqh within a short period. He became well-versed in 'ilm al-kalaam and debate, until he became the best of debater."

Ibn Rushd (Averroes), a rationalist, famously responded that "to say that philosophers are incoherent is itself to make an incoherent statement." Rushd's book, The Incoherence of the Incoherence, attempted to refute al-Ghazali's views, but the work was not well received in the Muslim community.

According to historian Firas Alkhateeb, "When one reads Imam al-Ghazali's works at a very superficial level, one can easily misunderstand what he is saying as anti-scientific in general. The truth, however, is that al-Ghazali's only warning to students is to not fully accept all the beliefs and ideas of a scholar simply because of his achievements in mathematics and science. By issuing such a warning, al-Ghazali is in fact protecting the scientific enterprise for future generations by insulating it from being mixed with theoretical philosophy that could eventually dilute science itself to a field based on conjecture and reasoning alone."

Al-Ghazali has been seen by Orientalist scholars as causing a decline in scientific advancement in Islam, because of his refutation of the new philosophies of his time. He purportedly saw danger in the statements made by philosophers that suggested that God was not all-knowing or even non-existent, which strongly contradicted his conservative Islamic belief. This position has been challenged, however. The following statement made by al-Ghazali has been described as evidence that he was not against scientific advancement: "Great indeed is the crime against religion committed by anyone who supposes that Islam is to be championed by the denial of mathematical sciences." This sentence, the source of which is not indicated in the cited book, is taken from Deliverance from Error. Ghazali does not mean that neglecting the study of mathematics would be a crime against science or against reason, but that rejecting them is a crime against religion. Its aim is not to promote the study of mathematics: it is to condemn the attitude which consists in considering them as rivals of religion. For him, religion has nothing to fear from them, because they do not deal with the same subjects. To condemn the study of mathematics for fear that it endangers religion is to mistake the place of each of them. This is clarified by the sentence which immediately follows: "For the revealed Law nowhere undertakes to deny or affirm these sciences, and the latter nowhere address themselves to religious matters. " A few pages later, he writes that the books of the philosophers must be banned - he defines philosophy as composed of six branches: mathematical, logical, physical, metaphysical, political, and morale. Al-Ghazali notably influenced Ibn Rushd, Ayn al-Quzat Hamadani, al-Nawawi, Ibn Tumart, Fakhruddin Razi, Suyuti, Tan Malaka, Thomas Aquinas, David Hume, Sayf al-Din al-Amidi, Asad Mayhani, Ali al-Qari, Muhammad Ibn Yahya al-Janzi.