That is, if the wife is ill, or unable to bear children, or unable to fulfill the husband's sexual needs, etc., taking a second wife is acceptable. As has already been pointed out, men are polygamous by nature. To try to curb it by such conditions will only lead to corruption in society. Feminists may object to this male right by insisting that women should also be able to practice polygamy. However, a woman marrying four husbands would only increase the problem of surplus women.
Divine legislation looks at the society as a whole seeking to maximize benefit.
If a certain legislation benefits the majority of the society and causes some emotional harm to a minority, the general welfare of society is given precedence.