ibn Rushd (Averroes) was one of the most important philosophers and theologians in Islamic history. Devoting most of his work to the defense of Aristotelian philosophy and reason, ibn Rushd, and the Mutazilites (an Islamic School of Thought) found themselves often in philosophical opposition with the Ashari (another Islamic School of Thought), and their iconic philosopher, al-Ghazali.

On what seems like a mirror of modern philosophical arguments about God, what differentiated al-Ghazali and the Ashari from ibn Rushd and the Mutazilites was the reliance on reason and revelation for believing in God. The Ashari argued one must know God through revelation, and that this knowledge went above and beyond any forms of reason. Conversely, the Mutalizilites, along with ibn Rushd, argued that one must understand God through reason before revelation.

ibn Rushd spent much of his life devoted to defending reason as the primary method of understanding God against the Ashari’s, and devoted a lot of time to explaining how studying philosophy is not just allowed in Islam, but is obligatory according to the Sharia.

In jurisprudence, he argued, there is a spectrum of judgments concerning actions. These actions can be split into five categories; where each action is either, Obligatory, Recommended, Approved, Disapproved, or Prohibited.

Since the Law encourages the study of existing beings, he argued, and philosophy is the study of existing beings, then the law encourages philosophy.

Because the law encourages it, the study of philosophy can be neither disapproved, nor prohibited. Because it is neither disapproved, nor prohibited, it is automatically considered to be approved. Taking it a step further, because the law does not just approve it, but encourages it, studying philosophy must be either an obligatory or recommended action.

ibn Rushd argues that the Sharia law encourages philosophy, and quotes passages from the Quran as proof of this. He argues that his interpretation of the Quran makes it obligatory for one to engage in intellectual reasoning.

He argues that philosophy is the study of existing beings, natural sciences, and other disciplines like physics, metaphysics, ethics, etc. Thus, he argues, it is obligatory to study philosophy.

ibn Rushd also advocated for collaborative philosophical efforts by encouraging Muslims to look to the “ancients” (Greeks) for knowledge. He argued that Muslims should be building off the achievements from past societies, instead of discarding previous knowledge and learning from scratch.

Regarding reason itself, ibn Rushd classified it into three classes, demonstrative reason, dialectic reason, and rhetorical reason. He argued, above all else, it was obligatory for the demonstrative class to study philosophy.

An apparent conflict rose on the issue of whether science and religion were compatible. ibn Rushd argued both could not conflict because both aim for the truth. The difference between the two, for him, was that philosophy, by nature, is demonstrative, whereas religion is metaphorical and interpretive.

ibn Rushd defined interpretation (tawil) as extension of significance of an expression from real to metaphorical.

He further argued that the demonstrative class of philosophy was only fit to interpret meanings of metaphors and observations. To let members of the other classes formulate interpretations was dangerous, according to ibn Rushd, since non-demonstratives would undermine the true meaning, or miss the meaning entirely, and not get the actual meaning of what is being interpreted across. He further argued that not anyone should be allowed to interpret, and that by keeping anyone from dong so keeps the religion from splitting into sects and dissension.

Disagreement, according to him, was not permissible on “principles of the Law”; only for “theoretical” issues. There was no unanimity on theoretical issues, and since theoretical issues were different from practical matters (which required definite answers for their daily lives), they could be discussed, but not in popular books.