Plurality of wives is not specifically prohibited by divine command in any religion; nor, except in the case of Islam, is the number of wives restricted. Islam permits a plurality of wives but restricts their number to four; and the permission is conditioned by just treatment of the wives:
“But if you feel you may not be able to deal justly between them, then marry only one.” (4:4).
Just treatment of wives, when there are more of them than one, means keeping an equality between them in the matter of maintenance, provision and companionship, that is to say, in such respects as are susceptible of equal apportionment. Equality is not prescribed in respect of such matters over which a person has no control, for instance, the degree of emotional attachment and inclination. This is excluded by the general principle:
“Allah requires not of anyone that which is beyond his capacity.” (2:287).
But there is also a specific exposition:
“You cannot keep perfect balance emotionally between your wives, however much you desire it, but incline not wholly towards one, leaving the other in suspense. If you will maintain accord and are mindful of your duty to Allah, surely Allah is Most Forgiving, Ever Merciful.” (4:130).
Some modern Muslim writers, in their anxiety and eagerness to curry favour with the West, have sought to argue that as polygamy was permitted on condition of equal treatment of wives (4:4) and equality was declared impossible of achievement (4:130), it follows that the permission was in effect revoked. This line of exegesis is entirely mistaken and is utterly untenable. The text of 4:130 itself clearly contemplates continuation of a system of plurality of wives. Besides, 4:130 was not interpreted by the Holy Prophet (peace be on him) or his companions as revoking the permission granted by 4:4; nor was such interpretation ever commended by Muslim Jurists through the centuries.
The truth is that polygamy as defined and restricted by Islam is a device designed by the highest wisdom for the fostering of high moral values and the safeguarding of chastity both of males and females. It may be described as a beneficent moral and cultural safety valve. For lack of such a safety valve, societies that have sought to enforce a rigid system of monogamy have been ripped apart by promiscuity, homosexuality, lesbianism and bestiality. Unrestricted sexual indulgence has become the norm between them, and does not even attract moral disapprobation.
The moral line is to be drawn not between monogamy and polygamy, but between regulation and license. In the absence of moral restraint, both monogamy and polygamy may be abused. It is the character of the relationship that exalts or debases it. As already mentioned, the ultimate purpose of marriage in Islam is winning the pleasure of Allah. Then Islam inculcates the beneficent development of all faculties and capacities through wise regulation and exercise, and disapproves of and condemns their suppression or stultification.
In the early years of Islam, responding to the divine call, particularly in the case of a male, spelt the forfeiture of life. Many paid the forfeit in Mecca; many more had to pay it in Medina and other places on the field of battle. Though women were not altogether exempt, yet comparatively few of them were called upon to make the extreme sacrifice. In consequence the number of women among the Muslims rapidly increased in proportion to men. Widows and orphans, male and female, had to be provided for. The safeguarding of moral and spiritual values, in these conditions, made polygamy an obligation, a sacrifice and certainly not an indulgence.
There were other considerations of a personal, social, politico-religious character, which called for polygamy. In modern times conditions have changed and monogamy, outside Africa, is becoming more and more the rule; but everywhere in individual cases moral considerations still call for a plurality of wives. Islam makes provision for such cases.
Among Muslims no stigma attaches to polygamy; it is as honourable as monogamy, and involves no discrimination between the wives or their children.