Since its introduction into the Islamic world, philosophy has faced relentless opposition and negative criticism throughout its history. This opposition, arising from disparate intellectual and theological concerns, was primarily expressed by three prominent groups: the religious scholars engaged in the study of jurisprudence (fiqh) and its foundational principles (usul), theologians, especially the Ash’arite school, and some mystics (Sufis). The intensity of this opposition was such that some equated the study of philosophy with apostasy and atheism, arguing that its core principles were fundamentally incompatible with the foundational tenets of Islam.
While opponents of philosophy have been many, al-Ghazali emerged as the most significant among them. With intellectual rigour and theological acumen, he effectively dismantled the secular intellectual environment within the Islamic world that had once allowed Muslims to engage with diverse scientific and philosophical debates. The culmination of this intellectual rupture was epitomised in his seminal work Tahafut al-Falasifah (The Incoherence of the Philosophers), in which al-Ghazali challenged the ideas of prominent peripatetic philosophers like Al-Farabi and Ibn Sina (Avicenna), exposing the contradictions and limitations of their philosophical systems.
Abu Hamid Muhammad al-Ghazali, an Ash’arite theologian and scholar of the Shafi'i school of jurisprudence, stands as one of the most influential figures in Islamic intellectual history. Well-versed in jurisprudence, theology, and dialectics, he is often criticised for contributing to the decline of philosophical inquiry within the Muslim intellectual tradition, especially in Sunni thought. Seyyed Hossein Nasr, a distinguished Iranian-American philosopher and theologian, maintains that al-Ghazali’s Tahafut al-Falasifah (The Incoherence of the Philosophers) decisively undermined rationalistic philosophy, and, in fact, brought an end to the philosophical tradition in the Arabic-speaking regions of the Islamic world. Frank Griffel, a respected scholar of Islamic studies at Yale University, offers a divergent view. He argues that although Al- Ghazali’s influence was undoubtedly significant, it did not lead to the complete obliteration of philosophy. Griffel contends that the existence of philosophers and philosophical works after Al-Ghazali—albeit in the minority—demonstrates that philosophy did not die entirely. There were those who continued to follow the teachings of Avicenna without engaging with Ghazali’s criticisms.
Critics argue that al-Ghazali’s influence led to a decline in the regard for rational thought in Islamic scholarship. However, this claim cannot be easily accepted or dismissed; it requires a careful examination of the broader historical context. A deeper inquiry into the three primary factors—the theological, methodological, and socio-political—will provide a clearer understanding of the reasons behind Al-Ghazali’s staunch opposition to philosophy.
First, with the fall of the Mu'tazilites, the Ash'arites emerged as the dominant orthodox school of Islamic theology. However, their doctrines did not achieve widespread acceptance until they were championed by scholars such as al-Juwayni and al-Ghazali, who is credited with refining and completing Ash'arite metaphysics. The Ash’arite school not only facilitated an independent critique of philosophy—especially Greek or Peripatetic philosophy—but also paved the way for intellectual contributions from figures like al-Ghazali and Fakhr al-Din al-Razi. Al- Ghazali's systematic refutation of philosophy, most notably in his celebrated work The Incoherence of the Philosophers, significantly diminished the apprehension toward intellectualism that had long prevailed among the orthodox. Some scholars, such as Ibn Rushd (Averroes), argued that Ash'arism, which they regarded as having evolved into the orthodox form of Islam, stifled the development of philosophy and science due to its emphasis on occasionalism. Critics often attribute the ascendancy of Ash'arism to al-Ghazali’s influence, as his works popularised Ash'arite theology to such an extent that it became the predominant theological framework of the Muslim community, a status it largely retains to this day. While the Ash'arites do not reject reason outright, they consider intellect (‘aql) secondary to Tradition (naql), prioritising the latter, in contrast to the Mu'tazilites. As Allama Iqal notes in The Development of Metaphysics in Persia, “Al-Ghazali was the first to write a systematic refutation of philosophy, and completely to annihilate that dread of intellectualism which had characterised the orthodox.”
In his pursuit of truth, al-Ghazali embarked on a rigorous spiritual journey, eschewing intellectual rationalism in favour of a more direct, experiential path. Ultimately, he found refuge in Sufism
Second, al-Ghazali’s critique of rationalism centres on the overreliance on reason and discursive philosophy. While he does not oppose or discredit intellect (aql) entirely, he argues that, although important, reason and intellect are insufficient for understanding absolute truth. His opposition to philosophy is articulated through two primary paradigms. First, al-Ghazali criticised Muslim peripatetic philosophers, particularly Ibn Sina and al-Farabi, for failing to meet the rigorous standards of demonstrative proof (burhan) and logic (mantiq), while elevating rational inquiry above the authority of Sharia and divine revelation. He contended that this elevation led to heretical and apostate views that undermined religious duties and deviated from core Islamic principles. In his The Incoherence of the Philosophers, al-Ghazali argued that the Aristotelian philosophy and logic transmitted by these philosophers were corrupt, often misinterpreted, and inadequate for addressing key theological matters. His critique focused on three central issues: the pre-eternity of the world, God’s knowledge of particulars, and bodily resurrection, among others. Secondly, as an Ash'arite theologian, al-Ghazali emphasised the epistemological primacy of Sharia over intellect. He believed that reason alone was insufficient to distinguish between good and evil or truth and falsehood. According to al-Ghazali, intellect must be subordinated to Sharia and divine revelation.
Al-Ghazali not only undermined the dominance of philosophy in the Islamic world, particularly within Sunni Islam, but also reinforced the centrality of Sharia in shaping both theological and moral understanding. Dr Fazlur Rahman Malik, a modernist scholar and Islamic philosopher, stated, "Having failed to satisfy orthodox requirements, [philosophy] was denied the passport to survival."
Third, al-Ghazali’s existential crisis, which began at the age of 38, precipitated a profound intellectual and spiritual turmoil, compelling him to abandon his prestigious career at Nizamiyyah Baghdad and personal life in search of the absolute truth and certitude. This crisis set him on a transformative, decade-long journey of epistemic inquiry. In his spiritual autobiography Deliverance from Error, he reflects on how the multiplicity of religious sects and conflicting doctrines within Islam fuelled his growing doubt. This realisation led him to reject conformist belief systems (taqlid), recognising religious adherence as more a result of social conditioning than rational conviction.
In his pursuit of truth, al-Ghazali embarked on a rigorous spiritual journey, eschewing intellectual rationalism in favour of a more direct, experiential path. Ultimately, he found refuge in Sufism, which he regarded as the only true path to absolute truth, transcending the limitations of reason and sensory perception, while rejecting all other intellectual and spiritual avenues, including philosophy. Al-Ghazali's immersion in Sufism led him to embrace an intuitive (shuhudi) methodology. In his view, philosophy was an intellectual exercise dependent upon sensory experience and reason—tools he deemed insufficient for attaining truth and certitude.
Al-Ghazali's intuitive methodology, as articulated in his writings, particularly in Ihya Ulum al- Din, emphasises the primacy of direct, experiential knowledge over abstract reasoning or intellectual debate. He contended that intuition (shuhud), being deeply subjective experience, could not be effectively communicated through traditional educational methods. In this regard, philosophy, with its reliance on rational analysis and logical constructs, appeared to al-Ghazali as a mere approximation of truth—incapable of guiding one to the deepest realities of existence, which could only be accessed through direct, mystical experience.
It is equally important to mention that al-Ghazali’s embrace of Sufism was not only the outcome of his intellectual and spiritual quest but also a response to the political climate of his time, which increasingly opposed philosophical inquiry. In particular, peripatetic philosophy came under severe criticism from traditional Sunni scholars. Due to various socio-political factors, the teaching of rational sciences in madrassahs was restricted, as exemplified by the Nizamiyyah in Baghdad, founded by Khwaja Nizam al-Mulk, where Ghazali both studied and later taught. Nizam al-Mulk, the Persian vizier of the Seljuk Empire, was a strong supporter of Shafi'i jurisprudence and Ash'ari scholars, and nearly all the teachers at the Nizamiyya were Shafi'i scholars. Furthermore, religious conflicts within the Islamic world were on the rise. In this context, the promotion and patronage of Sufism by the political elites, including Seljuk rulers such as Sultan Tughril Bey, his brother Ibrahim Yinal, and Nizam al-Mulk, can be seen as a response to both the political needs of the time and the intellectual turmoil within the Muslim world.
According to Seyyed Hossein Nasr, Ghazali's attacks on philosophy, as the leading Ash'ari theologian, Shafi'i scholar, and teacher at the Nizamiyya, played an important role in consolidating the political position and stabilising the Seljuk government.