Traditional Sunni and Shia Islamic marital jurisprudence allows Muslim men to be married to multiple women (a practice known as polygyny)—up to four wives at a time under Islamic law—with the stipulation that if the man fears he is unable to treat more wives fairly he must marry only one. Marriage by a woman to multiple husbands (polyandry) is haram (forbidden).
Contemporary views on the practice vary. Some non-Muslim secularists think it is no longer socially useful and should be banned (Rasha Dewedar). Some hold that it should be allowed only in cases of necessity (Muḥammad ʿAbduh). Still others feel it is part of the Islamic marriage system and that denying it is tantamount to denying "the wisdom of divine decree" (Bilal Philips and Jamila Jones).
Scriptural basis The verse most commonly associated with the topic of polygamy is verse 3 of Surah 4 An-Nisa (Women). A translation by Abdullah Yusuf Ali as:
It is believed these verses were revealed after the Battle of Uhud, so that some (Alia Hogben) argue that these verses have been revealed "because of Allah's concern for the welfare of women and orphans who were left without husbands and fathers who died fighting for the Prophet and for Islam.""Polygamy in Context." Common Grounds News Services. Alia Hogben. 02-Mar-2010. <http://www.commongroundnews.org/article.php?id=27379&lan=en&sp=0 >.
Others favoring this interpretation (Sunnipath), point out that the second part of verse Q.4:3 states "but if ye fear that ye shall not be able to deal justly (with them), then only one, or (captive women) that your right hands possess, that will be more suitable, to prevent you from doing injustice."
Other verses in the Quran that do not directly address the practice of polygyny by the faithful but discuss marriage generally, also have relevance to polygynous relationships.
Opinions of classical Islamic scholars Recommending monogamy While traditional Islamic scholarship upholds the notion that Islamic law permits polygyny, it emphasizes the divine command to "marry only one" where the man fears being unable to fulfil the rights of two or more in a fair manner, so that a substantial segment of the Islamic scholarship (using ijtihad, independent legal reasoning) argues that it is preferable for men to refrain from multiple marriages in most circumstances.
This opinion has been codified into the official positions of the Hanbali and Shaafi’i schools of jurisprudence which assert that it is "recommended" (i.e. mandub, one of the categories of fiqh ruling – halal, haram, wajib, etc.) for a Muslim male to have only one wife, even if he may act equitably with more than one woman.
Hanbali School Ibn Qudaamah from the Hanbali School of jurisprudence, said in Ash-Sharh Al-Kabeer: "It is more appropriate to marry only one wife. The author of Al-Muharrar [i.e. Abul Barakaat Al-Majd ibn Taymiyyah] said this, based on the saying of Allaah (which means) {...But if you fear that you will not be just, then [marry only] one}." [Ash-Sharh Al-Kabeer authored by Shams-ud-deen Ibn Qudaamah].
Shaafi’i School
"It is a Sunnah not to marry more than one wife if there is no apparent need." Ash-Shirbeeni from the Shaafi’i School of jurisprudence, [Mughni al-Muhtaj 4/207].
"Allah has permitted a man to marry up to four wives, saying: {...two or three or four...}, but Allah advised that it is desirable for man to marry only one wife, saying: {...But if you fear that you will not be just, then [marry only] one}". Al-Maawardi, from the Shaafi’i School of jurisprudence, [al-Hawi al-Kabir 11/417].
"It is fitter to confine oneself to just one". Imam Ahmed ibn Naqib al Masri, from the Shaafi’i School of jurisprudence, [Umdatu Salik].
"It does not call for two wives, [since] plurality may render life miserable and disrupt the affairs of the home." Imam Al-Ghazali, from the Shaafi’i School of jurisprudence, [Kitab al Nikah, Ihya Uloom ud Din].
Imam Shaafi’i, the founder of the Shaafi’i School of jurisprudence, offered an additional exegesis for the final clause of verse Q.4:3, which though usually interpreted as "that is more suitable that you may not incline to injustice", is better understood (Al-Shafi'i believed) as "that is more suitable that you may not be financially strained by numerous children"; his reasoning being that the verse had already listed fear of committing injustice as a reason to not wed more than once, hence it would be pointless for the same reason (for not wedding more than once) to be expounded twice in the same verse.
His alternative interpretation pursued the perception which held that the presence of a plurality of women in a man's conjugal life would produce undesirably large numbers of offspring, which could be a potential cause of financial hardship and poverty in the future.
Given the emphasis that Islamic law stipulates on the welfare of children and nurturing children with permitted means of income, Imam Shaafi’i opined that it was legislated for a man to marry just once as an increase in the population of a family due to multiple marriages could potentially harbour harmful monetary consequences for the man who marries more than once.
Ash-Shaafi’i is of the view that it is desirable to confine oneself to marrying only one although it is permissible for him to marry more than one. This is to avoid being unfair by being virilely incompetent, more inclined to some of them than others, or being unable to financially support them. [al-Hawi al-Kabir 11/417].
Contemporary sources Criticism of polygamy Modernist criticism Rasha Dewedar writes that after studying polygamy, early 20th century Modernist Muslim scholars such as Muhammad Abduh and Rashid Rida had concluded that polygamy was "an injustice to both women and children" for the following reasons: In most polygamous marriages men mistreat their wives and deny them their rights; Conflicts between the wives commonly spreads to tension among children; If an Islamic legal ruling has detrimental consequences, then according to the fundamentals of shari'a the ruling should be changed, based on the shari'a principle of “warding off evil takes precedence over bringing benefit".
Mistreatment of wives and tension among children being detrimental consequences, 'Abdu and Rida believed polygamy should only be allowed in cases of necessity. Another Modernist, Tahar Haddad, argued polygamy should be banned outright.
Dewedar herself argues that the verse most widely associated with polygyny (Q.4:3), was revealed after the Battle of Uhud and indicates that it must have been revealed "because of Allah's concern for the welfare of women and orphans who were left without husbands and fathers who died fighting for the Prophet and for Islam." Marriage was "the principal social protection system in that era" and a situation causing a big imbalance between the number of men and women could be remedied by polygamy.
Secular studies At least some systematic reviews of scientific studies of women and/or children in polygynous families (not all Muslim) have found negative results for mental health. A 2012 systematic review of 22 mental health studies of polygynous women (not all Muslim) compared to monogamous women report a "higher prevalence of somatization, depression, anxiety, hostility, psychoticism and psychiatric disorder in polygynous wives as well as reduced life and marital satisfaction, problematic family functioning and low self-esteem." Another systematic literature review, this one of 13 papers published between 1994 and 2014 found "more mental health problems, social problems and lower academic achievement for children and adolescents from polygynous than monogamous families". A 2021 systematic review and meta-analysis of psychological impact of polygamous marriage on women and children in 23 studies found "women in polygamous marriages had a 2.25 (95% CI: 1.20, 4.20) higher chance of experiencing depression (but not anxiety or distress, which were not found to be statistically significant) than in monogamous marriages." Children with polygamous parents had "a significantly higher Global Severity Index with a mean difference of 0.21 (95% CI: 0.10, 0.33) than those with monogamous parents."
Defence of polygamy Preacher Bilal Philips and Jamila Jones, strongly support polygamy in Islam, particularly in the face of what they believe are "restrictive impractical" Western norms, and the "loud new cry" raised by "so-called Modernist Muslims" against polygamy and easy divorce in traditional Islam. Philips and Jones point out polygyny predates Islam, that Muhammad and most major Companions of him (whose example Muslims traditionally are urged to follow), practiced polygyny. They further claim that worldwide the population of women exceeds the population of men (citing the statistic that in 1971 females made up 3% more of the population than males in the UK), and that this surplus population of women "unable to fulfill their sexual and psychological needs" within the bounds of marriage, will lead to a weakening of the "western family structure"; while no woman likes the idea of sharing her husband with another woman, Islamic law must give precedence to the general welfare and the Quran teaches that it is not possible to live without experiencing pain or tests from God, and that God's wisdom is superior to our opinions; it was only with the arrival of Western colonialism that Muslims began to question polygyny; the modernist criticism that polygamy is oppressive to women is wrong; men are more easily sexually aroused and have a higher rate of extramarital activity than women, and polygynous marriage has been, (and is), found outside of Westernized societies "with very few exceptions"; when a husband grows apart in interests from his first wife or she loses her beauty and he becomes interested in a younger woman, polygyny allows for him to take another wife without upsetting "family unity". the claim of non-Muslim Western men that they practice monogamy and control their sexual urges is false; these men actually pursue extramarital relationships in violation of their vows. According to Philips and Jones, "the fact is that institutional polygyny is vehemently opposed by male-dominated Western society because it would force men to fidelity".
Similarly, Shia cleric Muhammad Rizvi argues that criticism of polygyny in Western countries is part of the post-9-11 attack on Islam, and that those same countries which make polygamy illegal also suffer from "rampant" adultery and would do well to embrace the "practical religion", known as Islam whose "laws are in line with human nature", and allow men to have up to four wives.
Jurisprudence on polygamy An intermediate position between embracing polygamy and discouraging/banning it, is "adding conditions" to polygamous marriage. One condition in particular is requiring the consent of the first wife for the husband's taking another – the law in Egypt and several other countries. According to Islamic scholars giving fatwas on the issue, such consent is not required in Islamic law.
Some further comments made in fatwas on the subject are that: the husband should soften the blow with "good manners", "kindness" and however much money it takes to please the first wife, (The Standing Committee for Issuing Fatwas, Islam Online);