No rule of Islam is bereft of wisdom. The allowance for marrying more than once also has many benefits.
In this world, different people have different characteristics and conditions. For Nikah (marriage), people have been given different rules based on their capability and need. One marriage is permitted. If someone wants to marry more than once, then they can do so up to a maximum number of 4 marriages provided the husband can maintain justice between his wives and can fulfill their rights justly. If someone cannot maintain justice, then the marriage itself is permissible but the one who does not maintain justice will be considered a sinner. As Allah says:
And if you have the apprehension that you will not be able to treat the orphan girls justly then marry the women you like and who are lawful for you, two or three or four (but this sanction is conditional on justice). Then if you fear that you will not be able to treat (more than one wife) justly then (marry) only one woman or the maids who have come under your possession (in accordance with the Islamic law). This makes it more likely that you restrain you from committing injustice. Surah Nisa (4:3)
There are many benefits of permitting men to marry more than once and many social issues are solved through this. In married life, there are many problems which can lead to a stalemate and the only solution to them would be marrying another lady. There are various aims of marriage. Among them is propagation of human race. If, by any unfortunate chance, the wife is unable to bear children, then should the husband also be deprived of this bounty of Allah? Or should the man drive away this lady out of his house and marry someone else? If so, what would be the lot of that lady?
Islam provides the solution that marital relations should be maintained with this lady and the husband may marry a second time.
If for example, the wife is bed ridden for a long time and the husband’s needs remain unfulfilled, then the just solution would be marrying a second time.
If we look at it from a statistical point of view, the number of women is proportionately more than the number of men. Usually those kinds of work which are dangerous are by and large done by men, like for example fighting in wars. Women rarely and negligibly participate in these kinds of works. If men were to marry only woman, then the proportion of those women who have been widowed or have never been married would start climbing up in the society.
If a practical and just solution is not found for this, then the society will be ridden with moral diseases. The only practical and just solution for this is polygamy for men.
For all these reasons, Islam has given permission to marry up to 4 women. The condition is that the husband should be able to maintain justice between the wives and should fulfill all their rights (physical, economic, social, etc.) justly.
If the rights of any of the wives are trampled upon, then the husband will be considered a sinner and will be taken to account for this in Qiyamah.
The person who is not be able to fulfill the physical, economic, social rights of the wives equally and justly should not marry more than one lady. If in spite of this, this person does so, then the marriage itself will be permissible but this person will be considered a sinner for not maintaining justice between wives and for committing excess against his wife/wives.
And Allah (Subhanahu Wa Ta’ala) knows best.
Mufti Hafidh Syed Ziauddin Naqshbandi Qadri
[Professor, Islamic Law, Jamia Nizamia,
Founder/Director, Abul Hasanaat Islamic Research Center]