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

The women's rights in Islam include their right as wives in the marital relationship as well. In Islam, marriage is not confined to satisfying physical and emotional needs. There are many verses, stories, and narrations speaking about different aspects of marriage, including the mutual rights that the couple has over one another.

In this article, the rights of the wife over her husband have been summarized into the following two categories of financial and non-financial. It is noteworthy that this classification is embedded neither in the Quran nor the narrations and therefore, other classifications from other perspectives are also possible.

Financial Rights of Women as Wives

It is obligatory for a man to pay marriage portion (Sedaq) to his spouse as one of the most significant women's rights in Islam. The marriage portion is, by definition, a property which a husband gives his spouse upon marriage. This mandatory payment whether in the form of money or possession is upon husband until the time he fulfills it.

In due course, his wife has the right to either ask for or forgo it. In the case of forgoing, the husband is no longer required to fulfill this duty. Interestingly, in contrast with the idea which regards marriage portion as a price for a woman, a marriage without a fixed marriage portion is also correct [1].

But, how much should the marriage portion be? Islam has not specified the exact amount of the marriage portion. However, the amount of five hundred silver coins (Derham), which is equal to today’s $724.5 [i], fixed by the Prophet (PBUH&HP) for his wives and daughters is an encouraged model for Muslims. On account of this, it has been recommended that the marriage portion doesn’t exceed this fixed amount. Nevertheless, any amount of marriage portion that both parties agree upon is allowed by Islam [2].

Furthermore, a man is financially obligated to pay for the living expenses of his spouse (Nafaqah) including food, clothes, shelter, living necessities and the things that a wife usually needs in her life [3]. It makes no differences in this duty of the husband, whether his spouse earns money out of work or not, since she is not required to provide for the family [4].

As for the woman’s property, her husband also doesn’t have the right to take the outcome of her efforts into his possession [5]. Even if the wife asks wages for her works inside the house, the husband is supposed to pay, due to the Islamic laws [6]. God has underscored this supportive role of the men in the Quran as follows: “Men are the protectors and maintainers of women… (4:34)”

However, the man is responsible for arranging the comfort of his spouse as long as she does not disobey his legal demands [7]. Moreover, it makes no sense whatsoever to take the duty of providing the sustenance of the family as the sign of superiority of the man over his spouse [8].

When the husband dies his spouse inherits from him as well. According to the Islamic rules of inheritance, the woman is entitled to one-fourth of her spouse’s property in the case that he leaves no child as heir. But, if her spouse has any children, she is just entitled to one-eighth of her spouse’s property [9]. However, this topic in different cases includes some details which have been elaborated in the judicial sources.

Non-financial Women's Rights in Islam as Wives

The second type of women's rights in Islam concerns the moral rights of the wife. Our infallible Imams (A.S) reportedly advised their followers to be kind and respectful toward their wives and treat them gently. Prophet Muhammad (PBUH&HP) says: “The best of you are the ones who treat their family the best, and I am the best of you towards my family.” [10]

He, also, on various occasions recommended his companions to help their wives in the household chores and outlined many rewards for them regarding this act [11]. When some people inquired from him about the rights of a wife over her husband, he answered: “He should overlook her minor faults, and if she commits a major mistake then he should forgive her.” [12]

Imam Sajjad (A.S) has beautifully described women's rights in Islam and men’s moral duties toward their wives by demonstrating the blessings which God grants them through marriage: “The right of your wife is that you know that God has made her a repose and comfort for you; you should know that she is God’s favor towards you, so you should honor her and treat her gently.”[12]

Notes:
[i] This amount has been calculated based on the price of silver on 11th of November 2016. It may need further modification in future.  

References:

1. Islamic View on Human Rights: Viewpoints of Iranian Scholar.
2. wifes right
3. Ali Ibn Hussein Zaynul Abidin, A commentary on Imam Sajjad’s “The Treaties of Rights,” translated by Ali Peiravi, Ansariyan Publication.
4. Islamic View on Human Rights: Viewpoints of Iranian Scholar; this book is available at https://www.al-islam.org/.
5. Makarem Shirazi, Naser, 180 Questions Enquiries about Islam, translated by Shahnawaz Mahdavi, vol. 1.
6. Khorasani, Hussein Vahid, Islamic Laws, Create Space Independent Publishing, 2014, p. 393.
7. Hussein, Jamila, Islam, Federation Press, 2011, p. 109.
8. Kamrava, Mehran, The New Voice of Islam: Rethinking Politic and Modernity: a Reader, University of California, 2006, p. 163.
9. Shabir Khan, Muhammad, Status of Women in Islam, APH Publishing, 1996, p. 50.
10. Ali Ibn Hussein Zaynul Abidin, A commentary on Imam Sajjad’s “The Treaties of Rights”, translated by Ali Peiravi, Ansariyan Publication.
11. Javadi Amoli, Abdollah, Mafatih al-Hayat, Asra, 2012, p. 257.
12. Rizvi, Athar Hussein, Islamic Marriage, World Islamic Network.
13. Ali Ibn Hussein Zaynul Abidin, As-Sahifa Al-Kamilah Al-Sajjadiyya, Muhammadi Trust of Great Britain and Northern Ireland.