For more on this topic, see The Straight Path - Finding Guidance in an Age of Confusion
Tajdeed is mainly about restoration and adaptation
a. Uṣool-related ijtihâd that may have impeded the renewal of religious discourse
Rulings that differ whenever customs differ is not a [reflection of] any difference in the Divine instruction itself, for the Shariah was revealed to be permanent and eternal. Hypothetically, were this world to remain without end, and the people remained liable [to uphold the Shariah] as well, the Shariah would not need any additions. In other words, whenever customs change, they would fall under another [different] principle of Shariah that would govern them…
Mainly restoration and adaptation
Is renewable content limited to law?
Positions impeding the ongoing renewal of discourse
The question that remains is whether they [the Companions] truly reached consensus on a particular issue that was presented to them, while it is considered subject to ijtihâd. We may be able to answer this and say that there are many issues about which we do not know of any disagreement among the Companions regarding them. This is the most we could say. As far as claiming that they all reached a positive consensus, that is a claim that lacks supporting proofs. As for the following generations, after the expansion of Muslim territories and the relocation of the jurists to different Muslim lands, and many of the jurists among the followers of the Companions (tâbiʽeen) and others reaching distinction, whose numbers grew beyond count, with their variant political ideologies and personal interests, the claim of the establishment of a consensus then is not easy for one to accept. This is even though many issues during these times were not known to be subjects of disagreement. On such basis, we may be able to understand the statement of Aḥmad ibn Ḥanbal, “Whoever claimed a consensus has lied; maybe they disagreed; he should rather say, ‘I don’t know that they disagreed,’ if he did not hear of a disagreement.” Some Ḥanbali scholars posited that the imam means a consensus other than that of the Companions.
As for one who says, “I am not bound by anyone of the four imams,” if he meant he is not bound by a particular one of them as opposed to the rest, then he has spoken well; in fact, this is the correct of the two [known] positions. However, if he meant that he is bound by none of them and that he disagrees with them all, then surely he will be wrong most of the time. This is because the truth does not diverge from their positions in the vast majority of the [laws of] Shariah. People only disagreed whether the truth could be different from their positions in a few cases.
The proofs on the [authority of] consensus do not pertain to them (the agreement of the four imams), because they are among the believers of the ummah, and their status as imams does not change the rulings of ijmâʽ.
Flexibility Within Juridical Theory (Uṣool al-Fiqh)
The Shariah is based on wisdom and the pursuit of the welfare of humanity in their fleeting life and in the life to come. It is entirely just, wise, beneficial, and merciful. Anything that veers from justice into injustice, from mercy to its opposite, from wisdom to foolishness, and from the welfare of humanity to its harm, is not part of the Shariah, even if it has been included therein by misinterpretation.
A she-camel belonging to al-Barâ’ ibn ‘Âzib entered a man’s garden and ruined it. The Messenger of Allah ﷺ decreed that the property owners must safeguard their wealth by day, and the herd owners must keep their animals [from harming] by night.
Whenever the customs change, take that into consideration, and whenever they end, drop them (out of the equation), and do not be stiffly bound your entire life by that which is written in books. Similarly, when someone from outside your region comes to seek your fatwa, do not apply to him the norms (‘urf) of your town. Instead, ask him about the norms of his town and base your fatwa on them, not on the norms of your town or that which is established in your books. This is the plain truth; stiffness in applying the transmitted edicts is misguidance in the religion and ignorance of the objectives of the Muslim scholars and the pious predecessors.
He who issues fatwas to people based only on what is transmitted in books, despite the differences in their norms, customs, times, and places, and their own conditions, has gone astray and led others astray. His crime against the religion is greater than that of one who treats all people, regardless of their countries, customs, times, and personal inclinations, by that which is in the books of medicine. These ignorant muftis and physicians are the most damaging to the people’s religion and bodies. Allah alone is the one sought for assistance.
Flexibility in the existing theory of ijtihâd
It is permissible to follow any mujtahid one pleases, even after the codification of the madhâhib as is the case today. It is also permissible for him to transfer from his madhhab, but he should not seek out the concessions (rukhaṣ), and if he did, would he be a deviant (fâsiq)? [There are] two views. The commentator said, the most eminent view: [he is] not; and Allah knows best. In the beginning of At-tatârkhaniyah, [the author] wrote two chapters on religious decrees; the summary of the first is that Abu Yusuf said that issuing a fatwa is permissible only for a mujtahid, while Muhammad permitted it for anyone whose correct views are more numerous than his errors. It is reported from Al-iskâf that the most knowledgeable in a town has no excuse to avoid [issuing fatwas].
It is permissible for the non-mujtahid “to follow any mujtahid he chooses, if the madhâhib are codified like they are today.” Then, they may follow each of them in some issues, for the Companions used to ask someone one time and another one another time, without any denunciation [of this practice by any of them]. “He may also transfer from his madhhab” to another one, whether or not we said he is bound to seek the more knowledgeable or allowed him to choose any of them, as when he follows someone in their ijtihâd concerning the qibla sometimes and [follows] another one at other times. However, he may not seek out the concessions, for selecting them leads to the compromise of one’s religious dutifulness. “If he still chose them from the different madhâhib, would he become a deviant (fâsiq)? Two views; the more esteemed one: no.” This is different from one who selects them from the madhâhib that have not been documented, if he was in the early era, he would certainly not be a deviant (fâsiq), but if he is from the latter ages, it appears that he would become a deviant (fâsiq) for sure.
- That one does not seek out concessions wherever they are.
- That one does not compose a position which is rejected by consensus. (This applies mostly to talfeeq (patching or mixing of different positions).
Suggestions for Incremental Renewal
 Garraty, J. A., & Gay, P., The Columbia History of the World. New York: Harper & Row, 1985, p. 264.
 Collected by Abu Dâwood and al-Ḥâkim, who authenticated it on the authority of Abu Hurayrah. Sunan Abi Dâwood, verified by Muhammad Muḥyid-Deen ‘Abdil-Ḥameed. Beirut: Dâr al-Fikr, 4/109.
Ijtihad: to use one’s knowledge of the Qur’an, the Sunnah, and other Islamic sciences to derive rulings on matters not specifically or explicitly mentioned in either source of Islamic law.
 Madhhab (pl. madhâhib): a school of juridical or legal thought. The four schools in Sunni Islam are the Ḥanafi, Shâfiʽi, Mâliki, and Ḥanbali.
 Majallat al-ahkâm al-‘adliyyah, Article 39. This was also stipulated in different wordings by some of the most erudite scholars of uṣool, such as Ibn al-Qayyim, ash-Shâṭibi, ash-Shawkâni, and others.
 Raḍiya Allâhu ‘anhu: may Allah be pleased with him.
 Al-mu’allafati quloobuhum (at-Tawbah 9:60) are new or non-Muslims whose hearts the Muslims hope to win over.
 Sunan al-Bayhaqi al-kubrâ, 10/116, in the chapter ‘The Manners of the Judge, and What the Judge Rules By,’ Mecca: Dâr al-Bâz, 1414H.
 Ṣaḥeeḥ al-Bukhâri, 2/959, in the chapter ‘Treaties: Agreeing upon Unfair Terms Nullifies the Treaty,’ Beirut: Dâr Ibn Katheer wal-Yamâmah, 3rd ed., 1407 H; and Ṣaḥeeḥ Muslim, 3/1343, in the chapter ‘Verdicts: Nullifying False Rulings and Rejecting Innovations,’ Beirut: Dâr Ihyâ’ at-Turâth al-‘Arabi.
 Raḥimahu Allah: may Allah bestow mercy on him.
 Al-muwâfaqât by ash-Shâtibi, verified by ‘Abdullâh Drâz, Beirut: Dâr al-Ma‘rifah, 2/217.
 Since this article is mainly about ijtihâd-based tajdeed, my discussion of the intended restoration will be brief and only serves as a second introduction to the subject matter at hand.
 The “fatwa chaos” resulted in many odd and esoteric fatwas and teachings; many scholars attempted to regain control of the situation by shutting down independent ijtihâd (ijtihâd muṭlaq) and decreeing that it was allowed only for the scholars of the past.
 ‘Ilm uṣool al-fiqh by Abdul Wahhâb Khallâf, p. 260. Retrieved from Shamilah [computer software].
 Uṣool al-fiqh by Muhammad al-Khudari, pp. 313-314. Retrieved from Shamilah [computer software].
 I chose not to address the issue of insidâd bâb al-ijtihâd (closure of the gates of ijtihâd) declared near the end of the fifth century AH by many Muslim scholars who, after failing to properly regulate the practice of ijtihâd, intended to preserve the religion and protect it from the chaos of “ijtihâd” by unqualified individuals. It is hoped that most contemporary scholars are fully aware of the harmful effects of maintaining this position and how it could impede the development of Islamic law and its juridical theory.
 Uṣool al-fiqh by al-Khudari, pp. 313-314; See also, ‘Ilm uṣool al-fiqh by Khallâf, pp. 54-55.
 That is, one who yielded to sound proofs on an established consensus and then rejected the subject of that consensus, so he agreed that they agreed on a position but he subsequently rejected that position. Naqd marâtib al-ijmâʽ by Ibn Taymiyyah, Beirut: Dâr Ibn Ḥazm, 1419 H/1998 CE, p. 299.
 Ijmâʽ: consensus; a method of deriving rulings in jurisprudence.
 Tacit ijmâʽ (al-ijmâʽ al-sukooti) is when some mujtahidoon express their opinion concerning a religious matter, while the rest remain silent. There are many opinions about this type of ijmâʽ (see ‘Ilm uṣool al-fiqh by Abdul Wahhâb Khallâf, p. 51. Retrieved from Shamilah [computer software]).
 Mukhtaṣar al-fatâwa al-miṣriyyah by Badrul-Deen al-Baʽli, Cairo: Maṭbaʽat as-Sunnah al-Muḥamadiyyah, 1/61.
 Tuhfat al-muhtâj fee sharḥ al-minhâj by Ibn Ḥajar al-Haytami, Cairo: Al-Maktabah at-Tijâriyyah al-Kubrâ, 10/109. Retrieved from Shamilah [computer software].
 ‘Following the Four Schools of Law and the Ruling of Being at Variance with Them’ اتباع المذاهب الفقهية الأربعة وحكم مخالفتها. (n.d.). Retrieved August 14, 2017, from http://www.dar-alifta.org/AR/ViewFatawaConcept.aspx?ID= 187
 See Qawâ‘id al-ahkâm fi maṣâlih al-anâm by ‘Izz ad-Deen ibn ‘Abdil-‘Azeez ibn ‘Abdis-Salâm, Beirut: Dâr al-Kutub al-‘Ilmiyyah, 2/160.
 At-tamheed fi uṣool al-fiqh by Abu al-Khaṭṭâb al-Kallodhani. Makkah: Markaz al-Baḥth al-‘Ilmi wa Iḥyâ’ al-Turâth al-Islâmi, 1406 H/ 1985 CE, 3/281.
 Majmoo‘ al-fatâwâ by Ibn Taymiyyah, Taqi ad-Deen Aḥmad, Cairo: Maktabat Ibn Taymiyyah, 20/10.
 Sharḥ tanqeeḥ al-fuṣool by al-Qarâfi, Cairo: Sharikat aṭ-Ṭibâʽah al-Fanniyyah, 1973, p. 432.
 Tuḥfat al-muḥtâj by Ibn Ḥajar, Cairo: al-Maktabah at-Tijâriyyah, 1983, 1/47.
 Al-fawâkih al-dawâni by an-Nafrâwi, Beirut: Dâr al-Fikr, 1995, 2/356.
 See Fayd al-Qadeer by Abdul Raʽoof al-Munawi (d. 1031), Cairo: al-Maktabah al-Tijâriyyah al-Kubra, 1/210.
 Al-ijtihâd al-jamâʽi wa dawr al-fiqh fi ḥall al-mushkilât by Mustafa az-Zarqa, Jamʽiyyat al-Dirâsât wal-Buḥooth al-Islâmiyyah, p. 49.
 Resolution # 65 (7/3), Sixth Annual Conference of the OIC, 1412 AH/ 1992 CE.
 Majmoo‘ al-fatâwâ by Ibn Taymiyyah, 8/434.
 Târeekh Ibn Khaldoon by Abdul-Raḥmân Ibn Khaldoon, Beirut: Dâr al-Fikr, 1988, 1/651.
 I‘lâm al-muwaqqi‘een by Ibn al-Qayyim, Beirut: Dâr al-Kutub al-‘Ilmiyyah, 1991, 3/11.
 Al-maḥṣool by ar-Râzi, Beirut: ar-Risâlah Foundation, 3/74-75.
 Nafâ’is al-uṣool fi sharḥ al-maḥṣool by al-Qarâfi, Makkah: Nizâr al-Bâz, 5/2073-2074.
 Al-muhadh-dhab fi ‘ilm uṣool al-fiqh by Abdul-Kareem an-Namlah, Riyadh: Maktabat ar-Rushd, 1999, 5/2121.
 Kash-shâf al-qinâ’ by Manșoor al-Buhooti, Beirut: Dâr al-Kutub al-‘Ilmiyyah, 2/6.
 Al-inșâf fi ma‘rifat ar-râjih min al-khilâf ’alâ madhhab al-Imâm al-Mubajjal Aḥmad ibn Ḥanbal by ‘Ali ibn Sulaymân al-Mirdâwi, Cairo: Dâr Ḥajar, 1995, 5/91.
 Jâmiʽ al-masâ’il, qâ’idah fil-istiḥsân by Ibn Taymiyyah, p. 195. Retrieved from Shamilah [computer software].
 Al-iḥkâm fi uṣool al-aḥkâm by Al-Âmidi, Beirut: al-Maktab al-Islâmi, 4/157. Retrieved from Shamilah [computer software].
 See Naẓariyyat al-maṣlaḥah fil-fiqh al-Islâmi by Ḥusayn Ḥâmid Ḥassân, Dâr an-Nahdah al-‘Arabiyyah, 1971, p. 10.
 Dar’ ta‘ârud al-‘aql wal-naql [Refutation of the contradiction of reason and Revelation] by Ibn Taymiyyah (d. 728/1328) is all about this.
 Sunan Abi Dâwood, authenticated by al-Albâni (sunnah.com/abudawud/24/154).
 Al-furooq by Shihâb al-Din al-Qarâfi, ‘Alam al-Kutub, 1/191.
 I‘lâm al-muwaqqi‘een, 3/66.
 Majmoo‘ al-fatâwâ, 30/80. The hadith cited in this regard is not authentic.
 At-taqreer wal-taḥbeer ‘ala taḥreer al-kamâl, 3/352.
 Al-baḥr ar-râ’iq, 6/292. At-taqreer wal-taḥbeer, 3/352.
 Asna al-Maṭâlib fi Sharḥ Rawd aṭ-Ṭâlib by Zakariyâ al-Anṣâri, Cairo: Dâr al-Kitâb al-Islâmi, 4/286.
 At-tamheed by al-Kallodhani, 4/334.
 Al-‘uddah fi uṣool al-fiqh by Abu Ya’lâ al-Farrâ’, 5/1571. Retrieved from Shamilah [computer software].
 Nashr al-bunood ‘ala Marâqi as-So’ood by Abdullâh Ibn Ibrâheem al-‘Alawi, 2/270-271. Retrieved from Shamilah [computer software].
 Jâmi‘ bayân al-‘ilm wa faḍlih by Ibn ‘Abdul-Barr, 2/901. Retrieved from Shamilah [computer software].
 Sharḥ tanqeeḥ al-fuṣool, p. 432.
 See Al-baḥr al-muḥeeṭ by az-Zarkashi, 8/375, Dâr al-Kutbi, 1997. Retrieved from Shamilah [computer software]; Hâshiyat Ibn ‘Âbideen, 2nd ed., by Ibn ‘Âbideen, Beirut: Dâr al-Fikr, 1/48.
 See Al-fiqh al-Islâmi wa adillatuhu by Wahbah az-Zuḥayli, Damascus: Dâr al-Fikr, 1/106-107.
 Sharḥ tanqeeḥ al-fuṣool, p. 432.
 I‘lâm al-muwaqqi‘een, 1/6.
 See At-taqreer wat taḥbeer, 3/352.
 A reliable hadith reported by Imam Aḥmad and by ad-Dârimi with a good chain (sunnah.com/nawawi40/27).
 Sharḥ mukhtaṣar al-taḥreer by Ibn an-Najjâr al-Futooḥi, 14/74. Retrieved from Shamilah [computer software].
 Majmoo‘ al-fatâwâ, 24/69.
 Ahkâm al-Qur’ân by al-Qurṭubi, Cairo: Dâr al-Shaʽb, 1372 H, 9/287.
 See Al-mabṣoot by as-Sarakhsi, Beirut: Dâr al-Ma‘rifah, 30/51; Ahkâm al-Qur’ân by al-Qurṭubi, 9/287; Al-umm by ash-Shâfiʽi, Beirut: Dâr al-Ma’rifah, 1393 H, 5/234; Kash-shâf al-qinâ’, 4/356; and Al-mughni by ‘Abdullâh ibn Aḥmad ibn Qudâmah al-Maqdisi, Beirut: Dâr al-Fikr, 1405 H, 6/260.
 Tuḥfat al-mawdood by Ibn al-Qayyim, Damascus: Dâr al-Bayân, 1/267.
 Al-muhallâ by Ibn Ḥazm adh-Dhâhiri, Beirut: Dâr al-Âfâq al-Jadeedah, 10/316.
 Al-muhallâ, 10/316; Ahkâm al-Qur’ân, 9/287.
 See his books I‘lâm al-muwaqqi‘een and Aṭ-ṭuruq al-ḥukmiyyah.
 See the two previous books, in addition to Al-inșâf by Al-Mirdâwi, Cairo: Dâr Ḥajar, 1995, 10/233; Ibn Mufliḥ’s al-Furoo‘ , (6/85); and Ibn Taymiyyah’s As-siyâsah ash-sharʽiyyah , p. 136. The last two sources were retrieved from Shamilah [computer software].
 See his book Tabṣirat al-ḥukkâm fee uṣool al-‘aqḍiyyah wa manâhij al-aḥkâm: 2nd section, regarding the types of evidences.
 See Hâshiyat Ibn ‘Âbideen, 5/354.
 These are mentioned in order of the strength of their support for the use of qarâ’in and the scope of its use in their ijtihâd.
 ‘Umar (ra) found the Companions praying in the masjid in small groups, so he simply brought them together and had Ubayy lead them in prayer. Many of the Companions continued to pray at home. Some of them, including Ibn ‘Umar, considered it inferior if done at the masjid in congregation.
 An even more absurd suggestion we have heard is to make the tarâweeḥ start before ‘ishâ’.
 The first one to report it was Ibn Mujâhid al-Baṣri (d. 370 AH). It was contested by many scholars. Ibn Mujâhid (rh) was a resident of Basra, a city deeply traumatized two centuries earlier by the defeat of Ibn al-Ashʽath, which cost the lives of many of its eminent scholars in their fight against the Umayyads. One may ask if there is a basis in the Revelation that made them agree on this edict in the fourth century AH. If there is, how could it have been missed by all of the previous generations of the righteous predecessors and suddenly become so clear to them? If this agreement was based on reasoning related to public interest, which is most likely, then as Shaykh Shaltoot points out, such is the only consensus that may be abrogated by another upon a change in circumstances.
 Literally: ‘the people of authority.’ They are the elites, somewhat equivalent to today’s ‘representatives of the people,’ or the ‘senate.’ Traditionally, they were the princes, scholars, tribal chiefs, leaders of the army and various professions.