The idea of marrying more than one woman is greatly misunderstood, not least amongst Muslim men!
Context of Polygyny Verses
Before the advent of Islam, it was quite normal for a man to take many wives in marriage, or even to take them and not marry at all.
The Bible tells us that Solomon (Suleiman) had seven hundred wives and three hundred concubines!
It was a revolutionary thing to declare that a man may take up to four wives only. And there is more, because that permission must be understood in its proper context.
The verse allowing men to take more than one wife was revealed after the Battle of Uhud, in which 10% of the Muslim men had been killed.
Allah says what means:
And if you fear that you will not deal justly with the orphan girls, then marry those that please you of [other] women, two or three or four. But if you fear that you will not be just, then [marry only] one or those your right hand possesses. That is more suitable that you may not incline [to injustice]. (Quran, 4:3)
Now, in those days there was no kind of social security. If a woman didn’t have a husband, she had no one to provide for her. To put it simply, without a husband she would starve.
In a society where there were not enough men to equal the number of women wanting to marry, it was revealed that a man could take more than one wife.
But we must understand that this was to provide for her and to care for her. It is not a matter offulfilling sexual urges.
If Muslim men today are taking a second wife to spice up their own sex life, they are quite misunderstanding what Islam is saying.
In taking a second wife, a Muslim man should be taking a more pious wife or a woman who is in need.
In direct answer to your question, then, according to scholars, the Shari`ah does not require the husband to get the consent of the first wife for a second marriage.
This, of course, assumes that the conditions for a second marriage are right according to the Shari`ah. In such a case he can legally go ahead and marry.
But, as we have said, the permission to marry more than one wife is given in the Quran in the context of protecting widows, as they need to be taken care of.
Spirit of the Law Behind the Letter of the Law
In the very same verse it is stated clearly that if a man cannot treat his wives with equity, he should not marry more than one woman.
This is a clause usually ignored or taken lightly by many men, depriving women of the rights Allah Almighty has granted.
It is also worth mentioning that the bride has the right before marriage to require that her fiancé agrees in advance to certain conditions of hers, in case he is interested in pursuing another marriage later on.
Actually, this can be part of the marriage contract.
As it is the duty of Muslims to fulfill all obligations, the Muslim husband has no choice but to honor such a condition.
There is a very fine balance between understanding what a law says and also understanding what a law is intended for.
As Muslims, we seek to become Mu’mineen, or “good Muslims,” real men and women of faith. Islamic Shari’ah is intended to help us achieve that,insha’Allah.