Volume I — The Pillars of Faith (Qawaid al-Aqaid)

The second major book of the first volume of Ihya Ulum al-Din is Qawaid al-Aqaid — The Foundations of the Articles of Faith. This section demonstrates al-Ghazali's exceptional capacity to work on multiple intellectual levels simultaneously: he presents Islamic aqeedah in terms accessible to the ordinary believer while also engaging with the philosophical sophistication that the kalam (scholastic theology) tradition demanded.

Al-Ghazali begins with an affirmation of the six pillars of faith: belief in Allah, in the angels, in the revealed books, in the messengers, in the Last Day, and in divine decree (qadar) — good and bad. He then provides what he considers the correct creedal statement of Ahl al-Sunnah regarding each, following the Ash'ari school of which he is a distinguished representative. His exposition of the divine attributes — distinguishing the essential attributes (sifat al-dhat) from the active attributes (sifat al-fi'l) — reflects the sophisticated theological vocabulary developed by Ash'ari scholars to navigate between the twin pitfalls of anthropomorphism and negation.

One of the chapter's most interesting features is al-Ghazali's discussion of the different levels of certainty that different types of believers bring to their faith. He distinguishes three levels: the faith of the ordinary person ('awamm), who believes what they have been taught without deep investigation; the faith of the theologian (mutakallim), who has validated their beliefs through rational argumentation; and the faith of the gnostic (arif), who has attained direct spiritual knowledge (kashf) of the divine realities. Al-Ghazali argues that all three levels are valid forms of Islam, but they represent ascending degrees of knowledge and proximity to divine truth.

Al-Ghazali's treatment of divine attributes in this chapter is notable for its engagement with philosophical rationalism while maintaining the primacy of revelation. He does not simply quote Quranic verses but provides logical arguments for why the divine attributes must be as described — drawing on the concept of necessary existence (wujub al-wujud), which he inherited from and engaged with in the thought of Ibn Sina. His work Tahafut al-Falasifah (The Incoherence of the Philosophers), written parallel to the Ihya, demonstrates that this engagement was not uncritical — al-Ghazali was among the most rigorous critics of Islamic philosophical rationalism — but in the Ihya, philosophical vocabulary serves the purposes of explaining and defending revealed doctrine rather than displacing it.

The chapter concludes with a moving passage on the relationship between knowledge and action. Al-Ghazali warns that theological knowledge that does not transform the heart and motivate righteous action is a form of deception — a person may master every argument for the existence of Allah while their heart is occupied entirely by the love of this world. 'The heart is like a mirror,' he writes, 'and knowledge is like the reflection in it. But a mirror covered with rust cannot reflect. The rust on the heart is love of this world, and the polishing of the heart is remembrance of Allah, fear of Allah, and hope in Allah.'