Thus, it was fard on the Muslims to perform Ijtihād to deduce the Sharī’ah rule for each issue that occurred. And the rules that were deduced were Islamic Sharī’ah rules, deduced from the Quran and Sunnah or whatever the Quran and Sunnah alluded to in terms of evidences.
As for tafsīr (Qur’ānic exegesis), they used to explain the verses of the Qur’ān and attempted to expound the meanings of verses either according to what was indicated by the words and sentences, in terms of the linguistic and Sharī’ah meanings or by admitting things occurring which fell within the meanings of those words and sentences. Even though the tafsīr began to expand and the clarification of the meanings of verses became more detailed but Roman and Greek concepts relating to the viewpoint about life or legislation, considering them as coming from non-Islamic cultures were not inserted into the tafsīr literature. Indeed, there were fabricated and weak ahadīth used by some Mufassirun. They inserted their meanings into the tafsīr of the Qur’ān even though they were not Islamic. However, that is not to be considered as an example of being effected by non-Islamic culture but as interpolation of the Islamic culture, such as the interpolation of ahadīth the Messenger did not actually utter. There is a difference between interpolating something in Islam with respect to the fabrication of ahadīth and being effected by a non-Islamic culture by adopting its thoughts and inserting them into Islam as part of Islam. In short, the Sharī’ah disciplines were not affected by non-Islamic cultures. As for the literary and linguistic disciplines etc, the influence of the Arabic language on the rest of the languages in the conquered lands was strong until the other languages disappeared from common usage in life’s affairs. The Arabic language was the only dominant language over all affairs of life in its capacity as a political component in the understanding of Islam, because it is the language of the Qur’ān. That is why you will find that the conquered nations after having conviction in Islam participated in strengthening this influence because it was one of the requirements of Islam, the deen they came to profess. Therefore, Arabic language was not affected by the languages and culture of the conquered lands. On the contrary, the language itself influenced the land that was conquered and weakened its original languages until some of them disappeared altogether or almost disappeared with the Arabic language remaining as the only language of Islam, the only language used by the state, the common language, the language of culture, science and politics. Although Arabic literature came across material forms in the conquered countries such as gardens, palaces, seas, rivers, scenery etc, it grew with the increase in its meanings, imagination, similes and topics, it benefited from these but it did not become affected by thoughts which contradicted Islam. Thus, we find the aspects related to the creed which contradict Islam, none of the Muslim literary’s was affected by them and infact they completely opposed them. Although the Greek philosophy was translated and attention was given to it, however the Greek literature which professed belief in a plurality of gods and gave them anthropomorphic attributes did not gain much currency amongst the Muslims, in fact they did not give it any attention at all. Yes, some individuals did overstep the requirements of what was befitting the Islamic culture. They became vulnerable to meanings not recognised by Islam. Just as the morally depraved amongst the writers and poets did, they included meanings in their poetry which Islam did not agree with. But those were an insignificant few who are not worth mentioning in relation to the Islamic society. However much their literature may have been affected by meanings forbidden by Islam this was not an influence that affected the Islamic culture. Rather, the Islamic culture continued as did the Arabic culture and the Arabic language, free from any suspicion.
As for the rational disciplines, the Muslims due to the nature of their original mission in life, which is the Da’wah to Islam, used to clash with the people of other religions and cultures who would arm themselves with Greek philosophy. Refuting and destroying their beliefs and demonstrating their fallacy was imperative. They had to explain the Islamic ‘aqīdah (creed) in a manner these people could understand. That is why the Muslims instituted the science of Tawheed (belief in the oneness of Allah) in order to clarify the Islamic ‘aqīdah (creed) and explain it to the people. Thus, ‘ilm al-tawheed (science of Tawheed) came to exist. Even though it comes under the Sharī’ah disciplines in terms of the subject, which is the Islamic ‘aqīdah (creed), but it is considered part of the rational disciplines in terms of form and delivery. The Muslims benefited from mantiq (logic) and they translated it into Arabic. Consequently, it is clear that the foreign cultures did not affect the Islamic culture, whether in the Sharī’ah disciplines, Arabic language or rational disciplines. Only the Islamic culture remained until the end of the period of decline, as a purely Islamic culture. As for the Muslims they also were not affected by any other culture, neither in terms of their way of thinking or in their understanding of Islam. The mentality of the Muslims continued purely as an Islamic mentality. However, there were some individuals who were affected by the foreign rational disciplines. So, new thoughts arose amongst them. And there were individuals for whom the study of foreign philosophies was initiated as a veil over their minds which led them to fall into error in understanding some of the thoughts of Islam or led them to fall into misguidance in their intellectual discussions. They attempted to understand some of the thoughts without restricting themselves to the Islamic ‘aqīdah (creed) and the thoughts of Islam. They are two groups: The first group, it was the error in their understanding which caused them to fall into the situation they found themselves in, but they continued to have an Islamic mentality (‘aqliyya islamiyya) and Islamic disposition (nafsiyya islamiyya). Therefore, their intellectual contribution is considered part of the Islamic culture even though it contained erroneous thoughts, but it was a misunderstanding. The second group, the misguidance in their comprehension was what caused them to fall into the situation they found themselves in. They had completely deviated from the Islamic ‘aqīdah (creed) and came to carry a non-Islamic mentality (‘aqliyya). Therefore, their intellectual contribution is not considered to be part of the Islamic culture.
As for the first group, the effect of the Hindu philosophy was the reason for their error in their understanding. This is because the Hindu philosophy advocates ascetism and renunciation of the world. Some Muslims became confused and thought ascetism was the same as zuhd (pious austerity) which has been reported in some ahadīth. It is from this understanding that the Sufis arose. This affected the understanding of what it means to take or renounce the world. Even though zuhd (living an austere life) in this world means that one should not take the world as ones goal in life, for example, making the procurement of wealth for its own sake the highest goal. It does not mean however that one should not enjoy the good and halāl things in life which is contrary to ascetism and the renunciation of the world, both of which mean the abandonment of pleasures and delights in life despite having the ability to attain them. This contradicts Islam. This erroneous understanding originates due to the veil that covered the minds of some Muslims owing to their study of the Hindu philosophy.
As for the second group, their being effected by the Greek philosophy was the reason for their misguided understanding. This is because the Greek philosophy came with thoughts and discussions about things that were beyond the natural world. It set out to discuss the existence of God and His attributes (sifat). Those well-versed in it amongst the non-Muslims in the conquered lands attacked Islam which led some Muslims to translate their works and study them so as to respond to those attacking Islam. They tried to reconcile philosophy with Islam. This led to debates whose proponents were affected by the Greek philosophy such as the debate about the creation of the Qur’ān (khalq al-Qur’ān) and such as the debate about whether the attribute (sifat) was the same as the object being described or external to the thing described and other such discussions. But these discussions stopped at the limits of the Islamic ‘aqīdah (creed). Their proponents adhered to the ‘aqīdah (creed) and restricted themselves to its thoughts. The reasons for their discussions was the Islamic ‘aqīdah, they did not deviate from it. They did not proceed blindly into philosophy outside the applicability of the ‘aqīdah. Their thoughts were Islamic thoughts and their discussions are considered part of the Islamic culture. This is why they did not deviate or become misguided. Their adherence to the Islamic ‘aqīdah protected them from becoming misguided. Examples of such people are the Mu’tazila from scholars of tawheed. But there were a small number of people who plunged headlong into Greek philosophy without restricting themselves to the Islamic ‘aqīdah. They studied the Greek philosophy on a purely rational basis without adhering to Islam. They delved into the study of Greek philosophy and began to imitate and emulate it. They began to initiate their own philosophy based on their very own brand of philosophy. They did not permit the Islamic ‘aqīdah to have any effect on their discussions and nor did they acknowledge its presence rather their discussion was a purely philosophical discussion. Even though in their capacity as Muslims certain Islamic aspects did appear in their discussions but that was due to the deep-rooted Islamic concepts they held as was the case with some of the Jewish philosophers. This does not take their philosophy a single step closer to Islam rather it is a rational philosophy proceeding according to the methodology of Greek philosophy. They are the Muslim philosophers such as Ibn Sina, al-Farabi, Ibn Rushd and their likes. This philosophy of theirs was not Islamic and nor was it the philosophy of Islam concerning life, indeed it had no relationship to Islam. It is not considered as Islamic culture because the Islamic creed was not a part of its study. Rather, when they discussed it they did not give Islam any attention. Only Greek philosophy was the object of study and it has no relationship to Islam or the Islamic ‘aqīdah (creed).
This, briefly, is the position of Muslims with regards the non-Islamic cultures. So, the Muslims generally were not affected by them but they did benefit from them, and they definitely did not study the foreign cultures relating to legal rulings. In the Sharī’ah disciplines nothing can be found relating to the non-Islamic cultures. They benefited from the meanings, allegories and creativity present in the foreign cultures but that had no effect on the Arabic language or Arabic literature. So, from this perspective their study of non-Islamic cultures was by way of benefit and not effect. As for the rational disciplines, they studied them and benefited from them in terms of the style of delivery in logic (mantiq) and in ‘ilm al-tawheed. However, Islam and the thoughts of Islam were not affected but some Muslims were affected in their understanding of Islam and this manifested in their behaviour and writings but not in the Islamic culture or Islamic thoughts and this was the case with the likes of the Sufis and Muslim philosophers.
This is with respect to the culture. With regards to the sciences such as the natural sciences, mathematics, astronomy, medicine etc, the Muslims studied them and adopted them universally. They do not fall under culture which actually affects the viewpoint about life. They are empirical sciences only and general to all people. They are universal, not specific to any particular nation to the exclusion of others. Therefore, the Muslims took from them and benefited from them.
As for the manner of compiling the sciences and Islamic culture, it grew naturally until it was organised. The Islamic culture began orally, the people transmitted it to each other through hearing, they did not devote themselves to writing down anything other than the Qur’ān until the area of the state had expanded and there arose an urgent need to have the sciences and disciplines written down. Then, gradually the practise of writing increased though it was not according to any specific system. They would write about an issue in tafsīr, hadīth, jurisprudence, history, literature etc all in one book without arrangement or division into chapters because it all constituted knowledge in their view. There was no difference between one science and another or between one piece of knowledge and another. Rather, all were one science. A scholar was not distinguished by any particular science. Then there was a concentration on writing when the scope of the disciplines expanded and most became unable to encompass it all. So a specific inclination towards one type of science and discipline prevailed amongst each group. Thus, similar issues came to be gathered together. And the sciences and disciplines became more distinct and the Ulama began to slowly arrange it in an organised manner. Due to this the thoughts took the course of being arranged and written down until we have examples of such works as the Muwatta in hadīth, Kalila wa Dimna in Arabic literature, al-Risala in foundations of jurisprudence (usul), the books of Muhammad in jurisprudence (fiqh), the book al-’Ayn in Arabic language, and the book of Sibawayh in grammar, the book of Ibn Hisham in Sīrah, the book of Tabari in history and so on and so forth....rather there were books for each branch of fiqh (Islamic jurisprudence) like the example of Kitab al-Kharaj by Abu Yusuf regarding economics, and the book al-Ahkām al-Sultaniyya of al-Mawardi in ruling. Then the compilations included all branches of sciences and disciplines and the arrangement of issues (masa’il) and chapters gradually progressed until it came to include all the sciences and disciplines. Then culture (thaqafa) became separated from science in the compilations in the classes of higher education in the universities and so forth...
What is worth mentioning is that the Muslims took the style of compilation from others because the style of compilation is like the sciences in being general.