: Ibn-Rushd on the obligation to philosophise

Texts and Courses

Primary Texts

  • The Decisive Treatise (excerpted in D.E. Cooper and P.S. Fosl, eds., Philosophy: The Classic Readings)

Secondary Texts for Instructor

  • Taylor, Richard C. (2000) ‘“Truth Does Not Contradict Truth”: Averroes and the unity of truth’, Topoi 19: 3-16.
  • Taylor, Richard D. (2005) ‘Averroes: Religious Dialectic and Aristotelian Philosophical Thought’, in Peter Adamson and Richard C. Taylor (eds.), The Cambridge Companion to Arabic Philosophy (Cambridge: Cambridge University Press)

Suggested Courses

  • Introduction to Philosophy, Philosophy of Religion, Introduction to Ethics


Islamic culture was richly fed by many different sources. Islamic sources included the Qu’ran, kalām theology, the sunna and Hadith (records of the actions and sayings of the Prophet Muhammad) and a rich variety of legal and grammatical writings. Hellenic sources included many Platonic, Aristotelian, and Neoplatonic writings – not always distinguished at the time – and the insightful commentaries on the by falāsifa. But diversity brought problems of authority and priority and Islamic philosophers vigorously debated the relationship between Islamic and Hellenic sources. Although none argued for a crude dichotomization, delicate questions emerged about specific matters. How, for instance, should devout Muslims respond if philosophical reason requires modification of Islamic doctrine? Is absolute certainty in matters of faith only attainable through processes of philosophical demonstration, using Greek methods? Such questions reflected a complex ambivalence. On the one hand, Hellenic reason could both support and attack Islam. If Al-Kindī could use Aristotle to criticise the Christian Doctrine of Trinity, then he could be deployed against Islam, too. One influential response to these questions was given by Abu al-Walid Muhammad ibn Ahmad ibn Rushd  - latinised as Averroës. Drawing on his legal background, Ibn Rushd reframed the issue: should the study and practice of Hellenic-inspired philosophy be encouraged required of Muslims? Should it just be encouraged, or required, and, if so, why? Should all Muslims study philosophy or just those able and inclined?

Placing such philosophical questions in educational and legal contexts, Ibn Rushd’s explored these issues in his Decisive Treatise. At least two lines of argument were developed. The first plays on Aristotle’s doctrine of the Unity of Truth. If truths cannot contradict one another, and since Islam – as Allah’s definitive revelation – is true, then philosophy, done well, can only prove it to be so. To fear otherwise is either to misconceive philosophy or to lack faith in the truth of Islam. Successful or not, this argument does not, however, establish that Muslims are obliged to philosophise – only that their doing so would not contradict their religious faith. Ibn-Rushd therefore offers further arguments, some drawing on Quranic injunctions to enquire, others being more philosophical. Contestably defining philosophy as the ‘study of existing beings and reflection on them as indications of the Artisan’, Ibn-Rushd proposed that Muslims are indeed obligated – as a matter of religious law and faith – to study philosophy. Good Muslims are obliged, as a matter of religious integrity, to seek deep understanding of their faith, attainable only through philosophical reflection.

But a closer look at the Decisive Treatise shows a problem. Ibn-Rushd slips in the claim that the study of philosophy is ‘obligatory by Law’, but also only possible for those who have ‘natural intelligence’. But not everyone is naturally intellectually able and disposed – so is Ibn-Rushd adding the caveat that the study of philosophy is only obligatory for those with the relevant intellectual abilities? And if so, where does that leave those Muslims without the disposition or abilities to engage in demanding philosophy? This seems unfair to the ungifted, self-serving on the part of a philosopher, and a challenge to divine benevolence. The challenge is to articulate what philosophy adds to the life of faith, without simultaneously implying the poverty of lives of faith not thus shaped by philosophical reflection.

Discussion Questions

  • Is tradition a surer foundation for faith than reason?
  • What might philosophical reflection add to religious faith?
  • Is it elitist to say that a philosophical faith is better or deeper than a non-philosophical faith? If so, is that really a problem?


Ask the students to imagine reasons why it might be better to trust in a tradition – an historically inherited set of tried and tested ways of thinking, feeling, and living – than in the deliverances of philosophical reason. (You can divide them into two groups and have one argue for, the other against, the proposition). Help them to draw out arguments for and against the claim – for instance, the fact that tradition often provides a stability and constancy that philosophising does not; or that philosophy can play an essential role in exposing the tendencies of traditions to degenerate into dogmatic or stagnant forms. Once a suitably diverse range of arguments for and against tradition has been laid out, ask the students to consider Ibn-Rushd’s question about whether the study of philosophy should be obligatory for Muslims. Guide them toward subtler positions – like ‘division of labour’ accounts – that avoid ‘yes or no’ answers.

Author Information

Ian James Kidd (University of Nottingham)