A vow (Lat. votum, vow, promise; see vote) is a promise or oath. A vow is used as a promise that is solemn rather than casual.
Marriage vows
Marriage vows are binding promises each partner in a couple makes to the other during a wedding ceremony. Marriage customs have developed over history and keep changing as human society develops. In earlier times and in most cultures the consent of the partners has not had the importance now attached to it, at least in Western societies and in those they have influenced. Protestants, for instance, consider marriage vow as an unchangeable divine law since it needs not only "conciliar assertion" but also the support of the Scripture, making marriage a form of divine ordinance.
Divine vows
Within the world of monks and nuns, a vow is sometimes a transaction between a person and a deity, where the former promises to render some service or gift, or devotes something valuable to the deity's use. The vow is a kind of oath, with the deity being both the witness and recipient of the promise. For examples, see the Book of Judges. In the Roman Catholic Code of Canon Law, the vow and the oath are not considered acts of worship (cultus) like the liturgical celebration. However, they are considered acts of religion due to their sacred character, including the religious obligations they entail. Here, an important characteristic of the vow involves the manner by which non-Catholics are recognized to be capable of making a vow, which must also be fulfilled by reason of the virtue of religion.
Sometimes the old magical usage survives side by side with the more developed idea of a personal power to be approached in prayer. For example, in the Maghreb (in North Africa), in time of drought the maidens of Mazouna carry every evening in procession through the streets a doll called ghonja, really a dressed-up wooden spoon, symbolizing a pre-Islamic rain-spirit. Often one of the girls carries on her shoulders a sheep, and her companions sing the following words: This was explained further by St. Thomas Aquinas, who said:<blockquote>The obligation both of a vow and of an oath arises from something Divine; but in different ways. For the obligation of a vow arises from the fidelity we owe God, which binds us to fulfil our promises to Him. On the other hand, the obligation of an oath arises from the reverence we owe Him which binds us to fulfil our promises to Him.