According to the Catechism of the Catholic Church, it "is characterized by the public profession of the evangelical counsels of poverty, chastity, and obedience, in a stable state of life recognized by the Church".
The Code of Canon Law defines it as "a stable form of living by which the faithful, following Christ more closely under the action of the Holy Spirit, are totally dedicated to God who is loved most of all, so that, having been dedicated by a new and special title to his honour, to the building up of the Church, and to the salvation of the world, they strive for the perfection of charity in the service of the kingdom of God and, having been made an outstanding sign in the Church, foretell the heavenly glory."
What makes the consecrated life a more exacting way of Christian living is the public religious vows or other sacred bonds whereby the consecrated persons commit themselves, for the love of God, to observe as binding the evangelical counsels of chastity, poverty and obedience from the Gospel, or at least, in the case of consecrated virgins a proposal of leading a life of perpetual virginity, prayer and service to the church. The Benedictine vows as laid down in the Rule of Saint Benedict, ch. 58:17, are analogous to the more usual vows of religious institutes.
The Catechism of the Catholic Church comments: "From the very beginning of the Church there were men and women who set out to follow Christ with greater liberty, and to imitate him more closely, by practising the evangelical counsels. They led lives dedicated to God, each in his own way. Many of them, under the inspiration of the Holy Spirit, became hermits or founded religious families. Thus the Church, by virtue of her authority, gladly accepted and approved them."
Consecrated life may be lived either in institutes, societies, or individually. While those living it are either clergy or laypersons, the state of consecrated life is neither clerical nor lay by nature.
Societies of apostolic life are dedicated to pursuit of an apostolic purpose, such as educational or missionary work. They "resemble institutes of consecrated life" but are distinct from them. The members do not take religious vows, but live in common, striving for perfection through observing the "constitutions" of the society to which they belong. Some societies of apostolic life, but not all of them, define in their constitutions "bonds" of a certain permanence whereby their members embrace the evangelical counsels. The Code of Canon Law gives for societies of apostolic life regulations much less detailed than for institutes of consecrated life, in many instances simply referring to the constitutions of the individual societies. Although societies of apostolic life may in externals resemble religious life, a major distinction is that they are not themselves consecrated and their state of life does not change (i.e. they remain secular clerics or laypersons).
Examples of societies of apostolic life are the Oratory of Saint Philip Neri, the Daughters of Charity of Saint Vincent de Paul, and the Society of the Priests of Saint Sulpice, the Society of St Joseph of the Sacred Heart and the Missionary Society of St. Columban.
Besides institutes of consecrated life, the Catholic Church recognizes:
Each major development in religious life, particularly in the Latin West, can be seen as a response of the very devout to a particular crisis in the Church of their day.
When Constantine the Great was legalizing Christianity in the Roman Empire in the early 4th century, and the Christian faith became the favoured religion, it lost the self-sacrificing character that had profoundly marked it in the age of Roman persecution. In response to the loss of martyrdom for the sake of the Kingdom of God, some of the very devout men and women left the cities for the testings of the life in the desert that was meant to lead the individual back into a more intimate relationship with God, just like the wandering of the Israelites in the Wilderness of Sin. The Greek word for desert, eremos, gave this form of religious living the name eremitic (or eremitical) life, and the person leading it the name hermit. Anthony the Great and other early leaders provided guidance to less experienced hermits, and there were soon a large number of Christian hermits, particularly in the desert of Egypt and in parts of Syria.
Though the eremitic life would eventually be overshadowed by the far more numerous vocations to the cenobitic life, it did survive. The Middle Ages saw the emergence of a variant of the hermit, the anchorite; and life in Carthusian and Camaldolese monasteries has an eremitic emphasis. The Greek Orthodox and the Russian Orthodox Churches have their own eremitic traditions, of which Mount Athos is perhaps the most widely heard of today.
In modern times, in the Roman Catholic Church the Code of Canon Law 1983 recognises hermits who - without being members of a religious institute - publicly profess the three evangelical counsels, confirmed by vow or other sacred bond in the hands of their respective diocesan bishop, as Christian faithful that live the consecrated life (cf. canon 603, see also below).
The eremitic life was apparently healthy for some, but led to imbalance in others. Pachomius the Great, a near-contemporary of Anthony the Great, recognized that some monks needed the guidance and rhythm of a community (cenobium). He is generally credited with founding, in Egypt, the first community of monks, thus launching cenobitic monasticism.
Basil of Caesarea in the East in the 4th century, and Benedict of Nursia in the West in the 6th century, authored the most influential "rules" for religious living in their areas of the Christian world ("rule" in this sense refers to a collection of precepts, compiled as guidelines for how to follow the spiritual life). They organized a common life with a daily schedule of prayer, work, spiritual reading and rest.
Almost all monasteries in the Eastern Catholic Churches and in the Eastern Orthodox Church today follow the Rule of St Basil. The Rule of St Benedict is followed by a variety of orders of monastics in the West, including the Order of Saint Benedict, Cistercians, Trappists, and Camaldolese, and is an important influence in Carthusian life.
Canons regular are members of certain bodies of priests living in community under the Augustinian Rule (regula in Latin), and sharing their property in common. Distinct from monks, who live a cloistered, contemplative life and sometimes engage in ministry to those from outside the monastery, canons devote themselves to public ministry of liturgy and sacraments for those who visit their churches.
Around the 13th century during the rise of the medieval towns and cities the mendicant orders developed. While the monastic foundations were rural institutions marked by a retreat from secular society, the mendicants were urban foundations organized to engage secular city life and to meet some of its needs such as education and service to the poor. The five primary mendicant religious Order of the 13th century are the Order of Friars Preachers (the Dominicans), Order of Friars Minor (the Franciscans), Order of the Servants of Mary (Servite Order), Order of St. Augustine (Augustinians) and the Order of Our Lady of Mount Carmel (the Carmelites).
Until the 16th century recognition was granted only to institutes with solemn vows. By the constitution Inter cetera of 20 January 1521, Pope Leo X appointed a rule for tertiaries with simple vows. Under this rule, enclosure was optional, enabling non-enclosed followers of the rule to engage in various works of charity not allowed to enclosed religious. In 1566 and 1568, Pope Pius V rejected this classification, but their presence was tolerated and they continued to increase in number. Their lives were oriented toward social service and to evangelization in Europe and mission areas. The number of these congregations increased further in the upheavals brought by the French Revolution and subsequent Napoleonic invasions of other Catholic countries, depriving thousands of monks and nuns of the income that their communities held because of inheritances and forcing them to find a new way of living their religious life. On 8 December 1900, they were approved and recognised as religious.
The Society of Jesus is an example of an institute that obtained recognition as an "order" with solemn vows, although the members were divided into the professed with solemn vows (a minority) and the "coadjutors" with simple vows. It was founded in the wake of the Protestant Reformation, introducing several innovations designed to meet the demands of the 16th century crisis. Its members were freed from the commitments of common life, especially the common prayer, which allowed them to minister individually in distant places. Their unusually long formation, typically thirteen years, prepared them to represent the intellectual tradition of the Church even in isolation.
Secular institutes have their modern beginnings in 18th century France. During the French Revolution, the government attempted to dechristianise France. The French government had required all priests and bishops to swear an oath of fidelity to the new order or face dismissal from the Church, and had forbidden any form of religious life. Fr Pierre-Joseph de Clorivière, a Jesuit, founded a new society of diocesan priests, the Institute of the Heart of Jesus. He also founded the Daughters of the Heart of Mary (French: Société des Filles du Coeur de Marie). While living a life of perfection, they did not take vows, remaining a secular institute to avoid being considered a religious society by the government. They would eventually receive Pontifical institute status in 1952. The Daughters of the Heart of Mary, though resembling a secular institute in some ways, were recognized as an institute of religious life. On 2 February 1947 Pope Pius XII issued the apostolic constitution Provida Mater Ecclesia recognizing secular institutes as "a new category of the state of perfection" (Latin: nova categoria status perfectionis). The 1983 Code of Canon Law recognizes secular institutes as a form of consecrated life. They differ from religious institutes in that their members live their lives in the ordinary conditions of the world, either alone, in their families or in fraternal groups.