Polygamy has become an established part of traditional Islamic law and practice; Muslims are accustomed to accepting that a man's right to more than one wife is firmly established in the Qur'an and the Hadith. Polygamy (specifically polygyny, the marriage of one man to many women) is thus considered unquestionably moral, even though it is obviously unfair; only men are allowed the privilege of it. However, a close study of the Qur'an can enable one to see that the Islamic ideal of marriage is monogamous, with only husband-wife pairs. In fact, the Qur'anic stance on polygamy is the same as its stance on slavery; both are objectionable on ethical grounds, but tolerated due to the particular circumstances of Muhammad's community.

To begin, let us look at the Qur'anic verses relating to polygamous marriage:

If you fear that you will not act justly towards the orphans, marry such women as seem good to you, two, three, four; but if you fear you will not be equitable, then only one, or what your right hands own; so it is likelier you will not be partial.
{Surah 4 (an-Nisa), verse 3}

It should be immediately apparent that the Qur'anic stance on marriage is more complex than the traditional rule of upto-four-wives-at-once. To begin with, a man is only allowed more than one wife if they can be treated equitably. The stated purpose of polygamy is for the sake of social justice: to enable society to "act justly towards the orphans". In the context of Muhammad's early Medinan community this makes plenty of sense, as the widows and children of martyred Muslims had few options to fall back upon for survival other than remarriage. Since warfare against the Meccan opponents of Islam killed many of the male Muslims, it was necessary to allow their widows to remarry the surviving men. This would ensure that each widow and her children had a male to look out for their interests, without which their situation could have been difficult in the often patriarchal tribal society. This was especially important among the early Muslims of Medina, among whom much wealth was accumulated in the form of the spoils of battle and ransoms paid for enemies captured. Such wealth was controlled by the men who gained it in battle, and these were the ones who would have the means to provide for additional wives and children.

Polygamy is thus allowed to meet the specific needs of the early Muslim community at Medina. But what about in modern Muslim communities which have various institutions such as governmental and non-governmental agencies to look after the needs of destitute widows and orphans? The Qur'an simply does not provide any support for polygamy in this case. To resolve the question of whether or not polygamy is a universally applicable institution, we need to probe deeper into the Qur'an and discover whether it is ultimately moral. In this regard the following verse is important:

You will not be able to be equitable between your wives, be you ever so eager; yet do not be altogether partial so that you leave her, as it were, suspended.
(Surah 4 (an-Nisa'), verse 129}

Read alongside the previous verse, it becomes obvious that the practice of polygamy is morally questionable. In stark contrast to the previous allowance for multiple wives who are treated equitably, here the Qur'an flatly states that equitable behavior is impossible. The implication is that monogamy, and not polygamy, is the ideal for Muslims.

Polygamy must then be viewed as a temporary phenomena, allowed only due to the social needs of the Messenger's community. The Qur'anic stance on the ethical shortfalls of multiple marriages should result in their ultimate replacement by monogamy.

Traditional Muslim scholars have ignored the above possibility by treating only the verse permitting polygamy as legally valid. The other verse, implying that multiple marriage is immoral due to the impossibility of equitable treatment, was assumed to have no legal force. It was regarded only as an ethical injunction to encourage men to treat their wives well, even if they could not be completely fair. But this traditional interpretation misses the point. According to the Qur'an, the required equal treatment is impossible; thus polygamy is never completely ethical. Islamic law cannot be said to be "Islamic" if it does not fully incorporate Qur'anic ethics; thus polygamy cannot be universally permissible under Islamic law.

In discussing the ethics of marriage, we should realize that our commonplace perception of polygamy is profoundly influenced by our environment. On the one hand, the norm of industrial society has become monogamous marriage; thus the Islamic position seems oddly permissive in allowing a man more than one partner. Much anti-Muslim polemic has been directed against the 'sexual promiscuity' of the polygamous Muslim male. It is important to realize, however, that these laws were revealed under considerably different circumstances. In the context of pre-Islamic Arab society, the Qur'anic position represents a step toward monogamy rather than away from it. Before Islam, societal rules regarding sexuality and marriage were tribal in nature and relatively flexible. Both men and women were allowed multiple spouses; some of the types of "marriage" which prevailed were essentially approved forms of prostitution. A remnant of this permissive pre-Islamic ethic survives in the allowance in some Shi'i legal schools for temporary marriage (mut'a) whereby a couple can contract a marriage for an arbitrary fixed period, after which they are automatically divorced; the woman going her way with the bridal dowry, which cannot be returned. In this context, the Qur'anic legislation limited a woman to a single man and implied that monogamy was the moral ideal for men as well. The one-sidedness of the reform, initially limiting only polyandry (multiple husbands) and not polygyny (multiple wives), should be seen as an intermediate stage separating pre-Islamic sexual immorality and Islamic monogamy. Traditional Muslim legalists have been entirely concerned with the Qur'anic legal word on marriage, when the true issue should have been its moral position on sexuality.

Further evidence is available to uphold monogamy as the Islamic ideal. Regarding the Qur'anic view of sexual ethics, there is an extremely important area which has been traditionally ignored: slavery. Its immediate relevance to any discussion of Islamic sexual ethics becomes undeniable once we acknowledge the phenomenon of concubinage, that is, a free male's right to have sex with his unmarried slave-girl.

Prosperous are the believers who in their prayers are humble, and from idle talk turn away, and at almsgiving are active, and guard their private parts, save from their wives and what their right hands won, then not being blameworthy.
{Surah 23 (al-Mu'minun), verses 1-5}

"What their right hands own" (ma malikat aymanuhum) is a frequently used Qur'anic term for slaves. The quoted verse makes it legal for a man to engage in sexual relations with slave-girls whom he owns, thus making them his concubines without any marriage taking place between them. It is thus apparent that there are two kinds of sexual relationships which the Qur'an permits. Firstly, there is that which a man may have with his wife; secondly, there is that which he may have with his enslaved concubines. Thus we cannot develop a coherent picture of Qur'anic sexual ethics without incorporating a discussion of slavery.

The custom of enslaved concubinage is ancient in the Middle East. In the Bible, it is narrated that Abraham (the messenger Ibrahim in the Qur'an) was asked byhis childless wife Sarah to make a concubine of her slave Hagar, that he might thereby have a son. Their union produces his firstborn son, Ishmael (Genesis, chapter 16). A similar practice prevailed in pre-Islamic Arabia, and the Qur'anic verse quoted above allowed it to be incorporated into Islamic law. Muhammad may even have engaged in concubinage; his earliest biography, the biography (sirah) of Ibn Ishaq, mentions his Coptic slave Mariya, a gift to him from the governor of Egypt, as the mother of his son Ibrahim who died in infancy. Although some later Muslim historians have tried to claim that Mariya was Muhammad's wife rather than his concubine, the Sirah never explicitly states that he married her before the birth of their son. Even without this evidence from the Messenger's life, there can be no doubt that concubinage was an acceptable and legal practice among Muslims for centuries afterwards. One needs only look at the huge royal harems of the Abbasid Caliphs such as Harun al-Rashid's, which were populated by hundreds of concubines. These would almost all have to be enslaved concubines, as even the Caliph could have only four wives.

Slavery itself was an established part of bedouin Arab culture, and the Qur'an discouraged but never outlawed it. Slaves consisted of women and children captured from caravans or rival tribes whose freedom was not ransomed by their clan. The ransoms paid for captives and the wealth accumulated in the form of slaves gave slavery an important position of the economy of the period. Thus slavery could not be eliminated overnight without considerable social upheaval, which was undesirable in the already embattled and often unstable Muslim community of Medina. Thus slavery was allowed to persist, but the Qur'an established that to release slaves was a good deed, and should be done whenever possible to make up for one's moral shortcomings.

God will not take you to task for a slip in your oaths; but He will take you to task for such bonds as you have made by oaths, whereof the expiation is to feed ten poor persons with the average of the food you serve to your families, or to clothe them, or to set free a slave.
{Surah 5 (al-Maidah), verse 89}

Aside from expiation of wrongdoing, owners were encouraged to allow slaves to enter into a contract by which they would earn their freedom.

Those your right hands own who seek emancipation, contract with them accordingly, if you know some good in them; and give them of the wealth of God that He had given you.
{Surah 24 (al-Nur), verse 33)

So even though slavery is morally undesirable, the Qur'an continues to allow it in the context of the early Muslim community. However, the ethical encouragement to free slaves makes it obvious that Muslims are expected to move away from the practice. Concubinage would thus disappear along with slavery, leaving intramarital sex the only permitted option. The connection with marital and sexual ethics is apparent, since polygamy and concubinage together represent departures from monogamy. Both departures are ultimately discouraged, leaving Muslims with the ultimate ideal of monogamy.

Most Muslims have already accepted half of this argument in the form of the widespread belief that slavery is immoral. Yet Muslim conservatives, in attempting to preserve the traditional form of Islamic marriage, have ignored the Qur'anic implication that polygamy is similarly immoral. The connection between polygamy and slavery has not been properly treated, largely because concubinage has been ignored. It may be that conservative Muslims are embarrassed by its existence, since it represents a form of extramarital sexual activity that the Qur'an expressly tolerates, at least temporarily. From the perspective of Qur'anic sexual ethics, however, the polygamy-concubinage link cannot be overlooked; if slavery and concubinage can be opposed on ethical grounds, then so can polygamy.

In the Qur'an, polygamy and concubinage are two sides of the same coin. Both represent temporarily permissible practices as society progresses towards the ideal of sexual monogamy. The conclusions reached from our study all point towards this end. It seems that at least in this case, the laws of Muhammad's community were never intended to be extended beyond their particular historical context. This implication, of course, has immense consequences for the meaning and applicability of "Islamic law" as a whole.