There are many ways in which people come to be married, and they are all approvable - provided that those who are involved in the marriage are agreeable to it. There are many ways in which people come to be separated, or even divorced, but these necessarily do not require the agreement of everyone involved. The correct manner of conduct during such a separation, or divorce, is dictated by the manner by which the marriage was entered into, for termination and suspension of marriage is as much a part of the practice as the joining. But there are sometimes laws which must be considered: for sometimes, a kind of marriage or separation or divorce is legally prohibited. However, whether these laws are just, and either can or should be enforced, is a question of justice, not of marriage.
Women are understood to be the same as men in every way that is important when the formation, dissolution, duties and purpose of marriage is considered. Yet sometimes in marriage the duties of men and women are different, depending on the purpose and type of marriage formed, its purpose, and the agreements of those involved regarding the duties of the marriage.
The choice of whether marriage is undertaken between a man and a woman, between men and women, between a man and women, between women and a man, between women, or between men, depends on the purposes of the family.
There are many kinds of families which are formed by marriage, and it is for the purpose of forming these kinds of families that these marriages are undertaken. The purposes of family are many. Yet for all kinds, family is essential practice required for development and progress. Therefore, because the manner in which marriage is undertaken dictates the kind of family which will be formed by the union, the purpose of the family should guide the choice in what kind of family to form. Indeed, not every type of marriage, or family, is equally suited to every purpose. And each type of marriage has their purposes, advantages, and disadvantages: the choice of what kind of marriage is undertaken should be guided by the purpose of the intended family.
Separation occurs with the division of the family by distance, death, or sometimes even in accomplishing the purpose of the marriage. Sometimes it is for the purpose of separation that joining is undertaken.
Apart from separation, every marriage is understood to exist for a period of time. Sometimes, those joined will rejoin after the separation, sometimes not: this is determined by the Karma of the individuals, for they will require one type of family or another in their next joining depending on their accomplishments of their prior joining. Sometimes, a such a bond of friendship is formed between those joined that they remain in friendship after the termination, and may even desire to be joined again - but whether this is either possible or appropriate depends on their Karma.
There is frequently the situation where a union is made with the intention of remaining joined indefinitely. But these types of marriages come to an end, anyway.
There are many unions which are formed with the intention of short times, even for a day or a night, or an hour or less.
Yet no matter the term, those who are joined have, however briefly, formed a family and all the consenting parties should agree to and approve of the intended term of the union, and its purpose, and see that it is in conformity with the law. And that the rights of each member is respected in the termination.
There are many conditions upon which a marriage must be dissolved premature to its intended term: for failure of duty, for harm to one or more individuals involved - there are many valid and approvable reasons that the purposes of the marriage might not be possible.
Whether there is compensation owed to one party or another in this dissolution is determined by the manner of marriage, and its terms. And frequently the law. But most joinings result in a sharing of the products of that marriage, either equally, or not so equally.
The duties of marriage differ by the purposes of its making, and the manner by which it is formed, but in every case must be agreed to and approved by all participants. For while marriage is for the purpose of family, it is not for the purpose of a household (Grihastha) alone that joining is undertaken. It is appropriate and necessary to the accomplishment of Brahmacharya, Grihastha, Vanaprastha, and Sannyasa. Indeed, there is no difference between the family of monks, and a family of householders.
Nevertheless, there are numerous types of marriages which are not approvable: these must be dissolved as soon as possible in the manner of a divorce or separation, for the victims have rights to be regarded when they are forced into a marriage, or are incapable (by immaturity, senility, mental illness or other disability) from consenting to the terms of a marriage. Sometimes even those who are otherwise capable of consenting can be forced to marry: by coercion, threat, or even by slavery. These victims too must be compensated.
It is generally agreed upon that when marriage is made by purchase, or a marriage proceeds from material need, it is an approvable marriage. Frequently, the sharing of wealth is a purpose for marriage. Except when the one(s) being married do not benefit directly from the purchase, or did not approve of the terms, this can be construed as a form of slavery, where one or more persons are forced to join with another.
Similarly, it is not a joining when the participant(s) are merely companions, in consortium of friendship, through partnership. Partners, or consorts, while not slaves, are also not family - even if they share in the benefits of the consortium by direct payment or share, even if they have merged their households and families. For, without joining, without union, there can be no separation - and it is both the joining and the separation which constitute the practice of marriage.