A family in Islam is not only a place for reproduction but also a site for growing the healthy spirit and character of human beings. To clarify this point, some principles are mentioned below which are derived from the verses of the Quran:

1. Having amity and mercy within the family and providing security and peace for each other. This verse refers to family and its spiritual relations: “And of His signs is that He created for you mates from your own selves that you may take comfort in them, and He ordained affection and mercy between you. There are indeed signs in that for a people who reflect” (30:21).

2. Consultation and satisfaction of the couple in decision making [1].

3. In verse 71 of Al-Tawbah, men and women are introduced as each other’s friends and helpmates. In these verses, the importance of consultation is notified, and it is also mentioned that the viewpoints of all the family members are of equal value and no one’s approach receives more importance than the other’s [2].

4. The importance of family interests over personal interests [3].

5. Improving affairs and seeking reconciliation [4].

6. Forgiving each other’s mistakes, establishing peace and amour, and avoiding egocentricity: “If a woman fears from her husband misconduct or desertion, there is no sin upon the couple if they reach a reconciliation between themselves; and reconcilement is better. The souls are prone to greed; but if you are virtuous and God wary, Allah is indeed well aware of what you do” (4:128).

7. Being good-tempered in etiquette and commerce: “deal kindly with them” (4:19).

The principles mentioned above indicate that the style Islam suggests for families is achievable through a true collaboration of all family members. Every family is a small part whose rectification contributes to the improvement of the whole society and consequently its perfection.

References:

1. (2:233)
2. (9:71, 28:26, 28, and 37:102,103)
3. (2:229, 4:19)
4. (8:1)

As stated in the first part, Islam brought about reforms in the customs previous nations, including Arabs, had in practicing polygamy in Islam:

The Limitation in the Polygamy in Islam

The first reform Islam enforced was the restriction it imposed upon polygamy. Before the advent of Islam, there was no limit to the number of wives. One man could keep hundreds of wives and thus establish a harem for them, just as the ones some kings had, which is strictly banned in the religion of Islam.

However, Islam put a maximum limit on their number, and an individual was not allowed to have more than four wives simultaneously.

Justice:

The other reform that was made upon polygamy in Islam was the condition under which there must never be, for any reason, discrimination between the wives or their children. The Holy Quran explicitly commands:

"But if you fear that you may not treat them fairly, then [marry only] one" (4:3)

As a matter of fact, those men who can observe full justice with a number of wives are very few. It is clearly stated in the following verse of the Quran which is in association with the previous verse:

"you will not be able to be fair between wives, even if you are eager to do so..." (4:129)

Allah explains here that justice between the wives in its true sense - to stand exactly in the middle of the extremes - is beyond human power even if one may wish it. What a man is obliged to do is that he should not be totally inclined to one of them, leaving the other one as she were in suspense… [1].

Other conditions for Polygamy in Islam

Besides these two main restrictions, there are other responsibilities and duties polygamous men have to fulfill toward all their wives; such as Nafaqah (alimony) and Mahrieh (marriage portion), etc. [see the article about the rights of the wife over her husband]

The Best Form of Marriage in Islam

Ultimately, there is no dispute about the fact that monogamy is better; it is actually the best and most natural form of marriage in Islam. Obviously, the spirit of marital life which is oneness and unity is attained better and with more perfection with a single spouse.

It is only within this form of marriage that family commitment makes sense, and the great bond that unites the hearts of husband and wife makes them become one soul and one flesh [2].

Polygamy in Islam, on the other hand, rises from a social problem that rests heavily on the shoulders of all men and married women and for which a better solution has not yet been found. We have to face the fact that monogamy is not practical in specific social circumstances, and polygamy -under the mentioned conditions- is the most significant saving factor for monogamy.

A Choice between Conflicting Alternatives

One of two alternatives should be chosen: either the restricted acceptance of polygamy -as a duty rather than pleasure-, or the love affairs system, which is common in some societies these days. In other words, a few married men should marry more than one wife -of course under the condition of fulfilling all the above-mentioned responsibilities of a husband in a polygamous family-, and these will certainly not exceed a few percents, and unmarried women should settle, get home and make a life for themselves; or else open the way for love affairs.

In the case of the second alternative, the women deprived of family life may associate at her own free will with several men, and, as a result, almost all married men will in practice be polygamists.

Even then the matter will not end. The wives who will find their husbands to be unfaithful will think of taking revenge upon them and thus will themselves become unfaithful. This final result has been summarized in the well-known Kinsey report in one sentence: “The men and women of America have surpassed all other nations in unfaithfulness” [3].

Now, which alternative do you think is better?

References:

1. polygamy
2. Morteza Motahari, women and her rights in Islam, p. 148
3. Morteza Motahari, women and her rights in Islam, p. 150
4. polygamy in islam