A fraternity (Latin frater : "brother") is a brotherhood, though the term usually connotes a distinct or formal organization. The only true distinction between a fraternity and any other form of social organization is the implication that the members freely associate as equals for a mutually beneficial purpose, rather than because of a religious, governmental, commercial, or familial bond, although there are fraternities dedicated to each of these topics.

In many instances they are limited to male membership but that is not always the case, and there are mixed male and female, and even wholly female, fraternities. For example, for general fraternities; Grande Loge Mixte de France, Honorable Fraternity of Ancient Freemasons, Grande Loge Feminine de France, Order of the Eastern Star; for college and university fraternities, Alpha Phi International, Delta Delta Delta.

Fraternities can be organized for many purposes, including university education, work skills, ethics, ethnicity, religion, politics, charity, chivalry, other standards of personal conduct, asceticism, service, performing arts, family command of territory, and even crime. There is almost always an explicit goal of mutual support, and while there have been fraternal orders for the well-off there have also been many fraternities for those in the lower ranks of society, especially for national or religious minorities. Trade unions also grew out of fraternities such as the Knights of Labor.

The ability to organize freely, apart from the institutions of government and religion, was a fundamental part of the establishment of the modern world. In Living the Enlightenment, Margaret C. Jacobs showed the development of Jurgen Habermas' 'public space' in 17th century Netherlands was closely related to the establishment of lodges of Freemasons.

History

There are known fraternal organizations which existed as far back as ancient Greece and Rome and analogous institutions, called confraternities, which existed, allied to the Catholic Church, in the late medieval period.

The development of Freemasonry in the early 1700s became a watershed moment in fraternal organization, and there have been hundreds of varieties of Freemasonry, and thousands of closely parallel organizations since then. Virtually all fraternal organizations today bear some debt to the models of organization first worked out in Masonic lodges.

The development was especially dynamic in the United States, where the freedom to associate outside governmental regulation is expressly sanctioned in law. There have been hundreds of fraternal organizations in the United States, and at the turn of the last century the number of memberships was equal to the number of adult males, although, because of multiple memberships, probably only 50% of adult males belonged to any organizations. In 1944 Arthur M. Schlesinger coined the phrase "a nation of joiners" to refer to the phenomenon. Alexis de Tocqueville also referred to the American reliance on private organization in the 1830s in Democracy in America.