How did the different classical scholars define Iman?

In a Nutshell: The majority of classical scholars agree on the definition of Iman as "testimony and action" (qawl wa amal) and that it does increase and decrease. However, some classical jurists and theologians view Iman as only referring to conviction and exclude acts, denying it can increase or decrease. These include Abu Hanifah, Tahawi, Maturidi and the Shafi'i theologian Juwayni and others. Introduction The concept of Iman is somewhat problematic in Islamic discourse as it has different implications, usages and meanings in various Islamic texts. The term is used synonymously with the term Islam, as a set of fixed beliefs (Allah, his Books, his Angels, his Messengers etc), sometimes suggesting it comprises good deeds, whilst other times denoting belief in Allah. In this answer, I will consider the different definitions of Iman given by classical scholarship and put forward a brief analysis of these definitions. Evidences - Defining Iman Qur'an 1. هُوَ الَّذِي أَنزَلَ السَّكِينَةَ فِي قُلُوبِ الْمُؤْمِنِينَ لِيَزْدَادُوا إِيمَانًا مَّعَ إِيمَانِهِمْ – 48:4 It is He who sent down tranquility into the hearts of the believers that they would increase in Iman along with their [present] Iman. (Qur'an: 48:4) 2. إِنَّمَا الْمُؤْمِنُونَ الَّذِينَ إِذَا ذُكِرَ اللَّهُ وَجِلَتْ قُلُوبُهُمْ وَإِذَا تُلِيَتْ عَلَيْهِمْ آيَاتُهُ زَادَتْهُمْ إِيمَانًا وَعَلَىٰ رَبِّهِمْ يَتَوَكَّلُونَ - 8:2 The believers are only those who, when Allah is mentioned, their hearts become fearful, and when His verses are recited to them, it increases them in Iman; and upon their Lord they rely (Qur'an 8:2) 3. “The Messenger has iman in what has been sent down to him from his Lord, and so do the muminun. Each one has iman in Allah and His angels and His Books and His Messengers. We do not differentiate between any of His Messengers.” (Qur'an 2: 285) 4. “Rather, those with true devoutness are those who have iman in Allah and the Last Day, the Angels, the Book and the Prophets.” (Qur'an 2:177) 5. “Those who have iman in the Unseen and establish salat and give of what We have provided for them; those who have iman in what has been sent down to you and what was sent down before you, and are certain about the akhira.” (Qur'an 2:3-4) Sunnah 1. عَنْ أَبِي هُرَيْرَةَ، قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ الإِيمَانُ بِضْعٌ وَسَبْعُونَ أَوْ بِضْعٌ وَسِتُّونَ شُعْبَةً فَأَفْضَلُهَا قَوْلُ لاَ إِلَهَ إِلاَّ اللَّهُ وَأَدْنَاهَا إِمَاطَةُ الأَذَى عَنِ الطَّرِيقِ وَالْحَيَاءُ شُعْبَةٌ مِنَ الإِيمَانِ "‏ ‏ Abu Hurairah (ra) narrated the Messenger of Allah (saw) said: Iman has over seventy branches or over sixty branches, the most excellent of which is the declaration that there is no god but Allah and the humblest of which is the removal of what is injurious from the path and modesty is a branch of faith. (Sahih al-Muslim 1:60) 2. عَنْ أَبِي هُرَيْرَةَ، قَالَ النَّبِيُّ صلى الله عليه وسلم‏ "‏ لاَ يَزْنِي الزَّانِي حِينَ يَزْنِي وَهْوَ مُؤْمِنٌ، وَلاَ يَسْرِقُ حِينَ يَسْرِقُ وَهْوَ مُؤْمِنٌ، وَلاَ يَشْرَبُ حِينَ يَشْرَبُهَا وَهْوَ مُؤْمِنٌ، وَالتَّوْبَةُ مَعْرُوضَةٌ بَعْدُ ‏"‏‏ Abu Hurairah (ra) narrated: The Prophet (saw) said, "The one who commits an illegal sexual intercourse is not a believer (one with iman) at the time of committing illegal sexual intercourse and a thief is not a believer at the time of committing theft and a drinker of alcohol is not a believer at the time of drinking. Yet, (the gate of) repentance is open thereafter." (Sahih al-Bukhari 86:40) 3. عن عُمَرُ بْنُ الْخَطَّابِ قَالَ في حديث جبريل، عندما سأل النبي صلى الله عليه وسلم عن الإيمان‏ فقَالَ صلى الله عليه وسلم ‏"‏ أَنْ تُؤْمِنَ بِاللَّهِ وَمَلاَئِكَتِهِ وَكُتُبِهِ وَرُسُلِهِ وَالْيَوْمِ الآخِرِ وَتُؤْمِنَ بِالْقَدَرِ خَيْرِهِ وَشَرِّهِ ‏"‏ ‏.‏ قَالَ " صَدَقْتَ " ‏ Umar (ra) said: When Jibreel asked the Prophet (saw), "Tell me about Iman" The Prophet (saw) replied: "That you believe in Allah, His angels, His Books, His Apostles, the Day of Judgment and the Divine Decree about good and evil." (Sahih al-Muslim 1:1) 4. عَنْ عَبْدِ اللَّهِ، قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏ "‏ لاَ يَدْخُلُ النَّارَ أَحَدٌ فِي قَلْبِهِ مِثْقَالُ حَبَّةِ خَرْدَلٍ مِنْ إِيمَانٍ وَلاَ يَدْخُلُ الْجَنَّةَ أَحَدٌ فِي قَلْبِهِ مِثْقَالُ حَبَّةِ خَرْدَلٍ مِنْ كِبْرِيَاءَ ‏"‏ Abdullah ibn Mas'ud (ra) narrated the Messenger of Allah (saw) said: None shall enter the Fire who has in his heart the weight of a mustard seed of Iman and none shall enter Paradise who has in his heart the weight of a mustard seed of pride. 5. " وكذلك حديث وفد عبد القيس الذي رواه ابن عباس رضي الله عنهما أن النبي صلى الله عليه وسلم قال: " آمُرُكُمْ بِأَرْبَعٍ وَأَنْهَاكُمْ عَنْ أَرْبَعٍ، آمُرُكُمْ بِالإِيمَانِ بِاللَّهِ، وَهَلْ تَدْرُونَ مَا الإِيمَانُ بِاللَّهِ شَهَادَةُ أَنْ لاَ إِلَهَ إِلاَّ اللَّهُ، وَإِقَامُ الصَّلاَةِ، وَإِيتَاءُ الزَّكَاةِ، وَتُعْطُوا مِنَ الْمَغْنَمِ. Ibn Abbas (ra) narrated: The delegates of Abdul Qais came to Allah's Messenger (saw) and said, "The pagans of the tribe of Mudar intervene between you and us therefore we cannot come to you except in the holy months. So please order us to do something good (deeds) by which we may enter Paradise (by acting on them) and we may inform our people whom we have left behind to observe it." The Messenger (saw) said, "I order you to do four things and forbid you from four things: I order you to believe in Allah. Do you know what is meant by Iman in Allah? It is to testify that none has the right to be served except Allah, to offer prayers perfectly, to give Zakat, and to give Al-Khumus (one-fifth of the war booty). (Sahih al-Bukhari 97:181) 6. Ibn Abbas (ra) narrated the Prophet (saw) said to the deputation from Abd al-Qays, “I order you to do four things: have iman in Allah, and do you know what iman in Allah is? [It is] witnessing that there is no god but Allah, establishing the prayer, producing the zakat, fasting Ramadan, and giving the fifth of the booty.” (Muslim/Bukhari) Sahabah Some of the Prophet's (saw) companions provide evidence about the increase and decrease of faith. 1. إِنَّ مِنْ فِقْهِ الْعَبْدِ أَنْ يَتَعَاهَدَ إِيمَانَهُ وَمَا نَقَصَ مِنْهُ ، وَمِنْ فِقْهِ الْعَبْدِ أَنْ يَعْلَمَ أَمُزْدَادٌ هُوَ أَمْ مُنْتَقِصٌ ؟ Abu al-Darda (ra) said, "Part of a servant's knowledge is to understand one's iman and his weaknesses and to know if one's iman is increasing or decreasing." (Al-Lalika'i, Sharh Usul I'tiqad Ahlis-Sunnah wal-Jama'ah, Vol. 2, p. 40) 2. وقال عمير بن حبيب: الإيمان يزيد وينقص، قيل له: وما زيادته ونقصانه؟ قال: إذا ذكرنا الله فحمدناه وسبحناه فتلك زيادته، وإذا غفلنا ونسينا فذلك نقصانه. Umair ibn Habib (ra) said, "Iman increases and decreases. It was said, "How does it increase and decrease?" Umayr said, "If we remember our Lord and fear him, it will increase. If we are heedless and we forget and we waste our time, it will decrease."" (Bayhaqi, Shu'ab al-Iman, 55) Scholarly Views Arabic linguists agreed on the definition of Iman as linguistically meaning a convection (tasdiq) in the heart (Jurjani, Al-Ta'rifat; Ibn Manzur, Lisan al-Arab; Azhari, Tahzib al-Lugha) Classical jurists and theologians also agreed on considering tasdiq in the technical definition of Iman, however, they differed with regards to the inclusion of the acts in the definition of Iman (al-Bazdawi, Kitab usul al-Din, pp. 145-51) Kharijite: Iman is belief in heart and profession of that belief through the tongue accompanied with abstinence from all sins. Mutazalite and Shi'a: Iman is belief in heart and profession of that belief through the tongue accompanied with abstinence from major sins. Shafi'i and Ahl al-Hadith: Iman is both word and deed. Acts are part of iman, however iman is possible without corresponding deeds, i.e., not to be declared a disbeliever without them. Maturidite: Iman is belief in the heart and profession by tongue. Asharite: Iman is belief in the heart only. Murjiite: Iman is knowledge of God only along with profession. Karramite: Iman is profession by the tongue only. Ahl as-Sunnah wa al-Jama'ah Definitions of Iman Hanafis and Maturidis According to Abu Abu Hanifah, Iman does not change, meaning there is neither increase or decrease. وَالْإيمَانُ هُوَ الْإقْرَارُ وَالتَّصْدِيقُ وَإيمَانُ أهْلِ السَّمَاءِ وَالْأرْضِ لَا يُزَيِّدُ وَلَا يَنْقُصُ مِنْ جِهَةِ الْمُؤْمِنِ بِهَا وَيَزِيدُ وَيَنْقُصُ مِنْ جِهَةِ الْيَقِينِ وَالتَّصْدِيقِ، وَالْمُؤْمِنُونَ مستوون فِي الْإيمَانِ وَالتَّوْحِيدِ متفاضلون فِي الْأَعْمَالِ – الملا عي القاري، شرح كتاب الفقه الأكبر للإمام الأعظم أبي حنيفة 146-148 Iman means to affirm and be convinced. The faith of the inhabitants of the heavens [i.e. angels] and earth neither increases nor decreases in terms of the articles of faith; it increases and decreases in certainty and conviction. Believers are equal in faith and divine oneness, dissimilar in actions. (Mulla Ali Qari, Sharh al-Fiqh al-Akbar li Abu Hanifah, p. 143) Imam Abu Hanifah further argues against the notion of the increase and decrease of Imaan in his book al-Wasiya: ثَمَّ الْإيمَانِ لَا يُزَيِّدْ وَلَا يَنْقُصْ؛ لِأَنَّه لَا يَتَصَوَّرُ زِيادَةُ الْإيمَانِ إلّا بِنُقْصَانِ الْكَفْرِ، وَلَا يُتَصَوَّرُ نُقْصَانُ الْإيمَانِ إلّا بِزِيادَةِ الْكَفْرِ ، فَكَيْفَ يَجُوزُ أَنْ يَكُونَ الشَّخْصُ الْوَاحِدُ فِي حالَةٍ وَاحِدَةٍ مُؤْمِنَا وَكَافِرَا، وَالْمُؤْمِنُ لَا مُؤْمِنُ حَقَّا. وَلَيْسَ فِي إيمَانِ الْمُؤْمِنِ شَكٌّ ، كَمَا أَنَّه لَيْسَ فِي كَفْرِ الْكَافِرِ شَكٌّ ، لِقَوَّلَهُ تَعَالَى: (أُولئِكَ هُمُ الْمُؤْمِنُونَ حَقًّا). أي في موضع (أُولئِكَ هُمُ الْكافِرُونَ حَقًّا). أي في محل آخر والعاصون من أمة محمد صلى ‌الله ‌عليه‌ وسلم كلهم مؤمنون حقّا وليسوا بكافرين أيّ حقّا. Iman does not increase or decrease for its decrease cannot be conceived of except in connection with the increase of unbelief, and its increase cannot be conceived of except in connection with the decrease of unbelief. How is it possible for a single person to be a believer and an unbeliever at the same time, when the believer is in truth a believer and an unbeliever is in truth an unbeliever? There is no doubt in belief just as there is no doubt in unbelief, as Allah says, "They are in truth believers" (Qur'an 8:4) and "Such are unbelievers in truth" (4:151). And the disobedient ones from the ummah of Muhammad saw are all true believers and are not unbelievers [in truth]. (Ibid, p. 147) The author of the well-known Aqeedah Tahawiyyah, Imam Abu Ja'far Tahawi, also notes: وَالْإِيمَانُ: هُوَ الْإِقْرَارُ بِاللِّسَانِ، وَالتَّصْدِيقُ بِالْجَنَانِ. وَجَمِيعُ مَا صَحَّ عَنْ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ مِنَ الشَّرْعِ وَالْبَيَانِ كُلُّهُ حَقٌّ. وَالْإِيمَانُ وَاحِدٌ، وَأَهْلُهُ فِي أَصْلِهِ سَوَاءٌ، وَالتَّفَاضُلُ بَيْنَهُمْ بِالْخَشْيَةِ وَالتُّقَى، وَمُخَالِفَةِ الْهَوَى، وَمُلَازِمَةِ الْأَوْلَى. Iman refers to stating by the tongue and admitting by the heart. Truly, performing what is verified about the Messenger of Allah (saw) concerning Islamic law and the clear statements about what is right is a duty [for all people of Islamic faith]. Imaan is one and its people are the same in its origin. The preference between them is by fear of Allah, piety, fear of following one's heart, and adherence to the proprieties. (Ibid) Abu Mansur Al Maturidi of the Maturidi Islamic school of theology also viewed Iman as conviction: ثُمَّ قَدْ ثَبَتَ بِأدلةِ الْقُرْآنِ وَمَا عَلَيه أهْلُ الْإيمَانِ، وَالَّذِي جَرَى بِهِ مِنَ اللِّسَانِ أَنَّ الْإيمَانَ هُوَ التَّصْدِيقُ It has been proven by the Qur'an, the tradition of the people of Iman and the linguistic tradition that Iman is to be convinced. (Maturidi, Kitab al-Tawhid, p. 426) Majority of Ahl al-Sunnah The majority of Muslim jurists and hadith scholars like Malik, Shafi'i, Ahmed ibn Hanbal and Bukhari stated: قَوَّلَ وَعَمَلٌ ، وَيَزِيدُ وَيَنْقُصُ Iman is a testimony and actions, increases and decreases. (Ajiri, Al-Shari'ah, 65; Bayhaqi, Manaqib al-Shafi'i, Vol. 1, p. 385; Ahmed Ibn Hanbal, al-Sunnah, p. 68) Ibn Khaldun, in his Muqaddimah noted: أَنَّ الايمان الَّذِي هُوَ أَصْلُ التَّكاليفِ وَيَنْبُوعَهَا هُوَ بِهَذِهِ الْمَثَابَةُ ذُو مَرَاتِبِ أَوَلَهَا التَّصْدِيقَ الْقَلْبِيِ الْمُوَافِقِ لِلِسَانِ وَأَعْلَاهَا حُصُولَ كَيْفِيَّةٍ مِنْ ذَلِكً الِاعْتِقَادُ الْقَلْبِيِ وَمَا يَتْبَعُهُ مِنَ الْعَمَلِ مُسْتَوْلِيَةً عَلَى الْقَلْبِ فَيَسْتَتْبِعُ الْجوارحُ وَتَنْدَرِجُ فِي طَاعَتِهَا جَمِيعَ التَّصَرُّفَاتِ حَتَّى تَنْخَرِطَ الْأَفْعَالَ كلَهَا فِي طَاعَةٍ ذَلِكً التَّصْدِيقَ الإيماني، وَهَذَا أَرَفْعُ مَرَاتِبِ الايمانِ وَهُوَ الايمانُ الْكَامِلُ الَّذِي لَا يُقَارِفْ الْمُؤْمِنُ مَعَه صَغِيرَةً وَلَا كَبِيرَةً إِذْ حُصُولُ الْمَلِكَةِ وَرُسُوخُهَا مَانِعٌ مِنَ الْاِنْحِرافِ عَنْ مَنَاهِجِهِ طُرْفَةٍ عَيْنَ Iman is the basis and source of all the (religious) obligations, is of that type and has several degrees. The first degree is the affirmation by the heart of what the tongue says. The highest degree is the acquisition, from the belief of the heart and the resulting actions, of a quality that has complete control over the heart. It commands the actions of the limbs. Every activity takes place in submissiveness to it. Thus, all actions, eventually, become subservient to this affirmation by faith, and this is the highest degree of faith. It is perfect faith. The believer who has it will commit neither a great nor a small sin. The acquisition of the firmly rooted habit (of faith) prevents even the briefest deviation from its ways. In addition, some scholars such as Shafi'i, Bukhari, Baghawi and ibn Abdul Birr conveyed the ijma (consensus) of companions and their successors that Iman consists of qawl and amal. (Al-Lalika'i, Sharh Usul I'tiqad Ahlis-Sunnah wal-Jama'ah, Vol. 5, p. 956; Ibn Taymiyyah, Majmu al-Fatawa, Vol. 7, p. 209; Ibn Abd al-Birr, Al-Tamhid, Vol. 9, p. 238) Al-Shafi'i said: وَكَانَ الْإِجْمَاعُ مِنَ الصَّحَابَةِ، وَالتَّابِعِينَ مِنْ بَعْدَهُمْ مِمَّنْ أَدَرَكَنَا: أَنَّ الْإيمَانَ قولٌ وَعَمَلٌ وَنِيَّةٍ لَا يُجْزِئُ وَاحِدٌ مِنَ الثَّلاثَةِ عَنِ الْآخَرِ The consensus of the companions and the successors after them and those we caught up with say: Iman is a verbal pronouncement, a deed and an intention. (Al-Lalika'i, Sharh Usul I'tiqad Ahlis-Sunnah wal-Jama'ah, Vol. 5, p. 956) Bukhari stated: لُقِيتِ أَكْثَرُ مِنْ أَلُفُّ رَجُلً مِنْ أهْلِ الْعِلْمِ كُلُّهُمْ يَقُولُ: الْإيمَانُ قولُ وَعَمَلَ I have met more than one thousand men of knowledge all of them saying Iman is a word of mouth, a deed. (Al-Lalika'i, Sharh Usul I'tiqad Ahlus-Sunnah wal-Jama'ah, Vol. 1, p. 174) Mutazilites and Kharijites Mutazilites and Kharijites agreed with the majority of the scholars of Ahl al-Sunnah in their definition of Iman as it comprises actions, statements and beliefs. However, they disagreed with them by viewing that Iman is indivisible. Therefore, they viewed committing major sins makes a person outside faith. As for the Kharijites, they called this person infidel (kafir), whilst the Mutazalites placed this person "in a station between the two" (i.e. the believer and unbeliever). Analysis of Definition of Iman The difference of opinion between Abu Hanifah, Tahawi, Maturidi etc and the other group of scholars is based on the inclusion or exclusion of acts of obedience in the understanding of Iman. According to the former, iman does not increase, because faith is the name of firm conviction (tasdiq jazim) coupled with submission (idh'iin), and this does not change by obedience or sin. However, it has been said this difference about the inclusion of acts is a semantic one. The interpreter of Aqeedah Tahawiyyah, ibn Abi al-Izz al-Hanafi, says: وَالْاِخْتِلاَفُ الَّذِي بَيْنَ أَبِي حَنِيفَةً وَالْأئِمَّةَ الباقين مِنْ أهْلِ السُّنَّةِ - اِخْتِلاَفُ صُورَِيٍ . فَإِنَّ كَوْنَ أَعْمَالَ الْجوارحِ لاَزِمَةً لِإيمَانِ الْقَلْبِ ، أَوْ جُزْءَا مِنَ الْإيمَانِ ، مَعَ الْاِتِّفَاقِ عَلَى أَنَّ مُرْتَكِبَ الْكَبِيرَةِ لَا يَخْرُجْ مِنَ الْإيمَانِ ، بَلْ هُوَ فِي مَشِيئَةٍ اللَّهِ ، إِنَّ شَاءَ عَذَّبَهُ ، وَإِنَّ شَاءَ عَفَا عَنْه - نِزَاعُ لَفْظِيٍّ ، لَا يَتَرَتَّبُ عَلَيه فَسَادُ اِعْتِقادٍ . The difference between Abu Hanifah and other imams, to avoid ambiguity is a difference in form only, not in context. The difference is whether the physical actions are essential for the faith of the heart or partly essential since they agree that the sinner is not excluded from faith, but he is under the will of Allah; if He so wills, he is punished, and if He wills, he is forgiven. It is only a matter of wording and the problematic assumption is not based on it. (Sharh al-Aqeedah at-Tahawiyyah) The two parties do not differ in the importance of physical action in Islam, they differ as to whether it is part of faith or an injunction. Those who consider it part of faith do not put it on the same level as attestation by tongue or admittance by the heart, whereas their absence would indicate elimination of faith, whilst iman would be present in the absence of physical actions. The others, though they do not consider it a constituent of faith, see it as essential. There is a preceding argument concerning the differences between the two parties in defining Iman, which is the increase and decrease of Iman. Those who add deeds and actions to faith hold such opinions, while those who limit faith to utterance and heart confirmation do not. In fact, their difference in this case is also theoretical because the party that does not consider the increase and decrease of Iman declares people are compared and preferred by piety and good work. They vary in their reward and position in the eyes of Allah. Imam Tahawi says: وَالْإِيمَانُ وَاحِدٌ، وَأَهْلُهُ فِي أَصْلِهِ سَوَاءٌ، وَالتَّفَاضُلُ بَيْنَهُمْ بِالْخَشْيَةِ وَالتُّقَى، وَمُخَالِفَةِ الْهَوَى، وَمُلَازِمَةِ الْأَوْلَى. Iman is one and its people are the same in its origin. The preference between them is by fear of Allah, piety, fear of following one's heart, and adherence to the proprieties. (Ibid, p. 86; Aqeedah Tahawiyyah, p. 375) Conclusion Iman for the majority is a verbal pronunciation, a deed and an intention based on textual proofs. It increases with an increase in acts of obedience and decreases with a decrease in them. References Abu Hanifah, Al-Fiqh al-Akbar Ahmed Ibn Hanbal, al-Sunnah Ajiri, Al-Shari'ah Al-Bazdawi, Kitab Usul al-Din Azhari, Tahzib al-Lugha Bayhaqi, Manaqib al-Shafi'i Ibn Abd al-Birr, Al-Tamhid Ibn Abi al-Izz, Sharh al-Aqeedah at-Tahawiyyah Ibn Hazm, Al-Fisal Ibn Manzur, Lisan al-Arab Ibn Taymiyyah al-Rasa'il wa al-Mas'il Jurjani, Al-Ta'rifat Tahawi, Al-Aqeedah al-Tahawiyyah Maturidi, Kitab al-Tawhid Muhmad Na'im Yasin, Al-Iman: Arkanuh, Haqiqatuh, Nuaqaduh Mulla Ali Qari, Sharh al-Fiqh al-Akbar for Abu Hanifah