A hermit (from the Greek erēmos, signifying "desert", "uninhabited", hence "desert-dweller") is a person who lives to some greater or lesser degree in seclusion from society.
Originally the term was applied to a Christian who lives the eremitic life out of a religious conviction, namely the Desert Theology of the Old Testament (i.e. the 40 years wandering in the desert that was meant to bring about a change of heart).
Often – both in religious and secular literature – the term is used loosely for anyone living a solitary life-style – including the misanthropist – and in religious contexts is sometimes assumed to be interchangeable with anchorite/anchoress (from the Greek anachōreō, signifying "to withdraw", "to depart into the country outside the circumvallated city"), recluse and solitary. However, it is important to retain a clear distinction.
Christian hermits in the past have most often lived in caves, forests, or deserts, but some of them preferred an isolated cell in a monastery or even a city. From what we know from their contribution to our Christian heritage, male hermits were more common than female. As regards the anchorites, one that has left a lasting impression on Christian spirituality is the English anchoress Julian of Norwich.
Hermits in religion
From a religious point of view, the solitary life is a form of asceticism, wherein the hermit renounces wordly concerns and pleasures in order to come closer to the deity or deities they worship or revere. This practice appears in Christianity, Hinduism, Islam, and Buddhism. In ascetic hermitism, the hermit seeks solitude for meditation, contemplation, and prayer without the distractions of contact with human society, sex, or the need to maintain socially acceptable standards of cleanliness or dress. The ascetic discipline can also include a simplified diet and/or manual labor as a means of support; for example, the early Christian Desert Fathers often wove baskets to exchange for bread.
Ironically, religious hermits are often sought out for spiritual advice and counsel and may eventually acquire so many disciples that they have no solitude at all. Examples include Anthony the Great, who attracted such a large body of followers in the Egyptian desert that he is considered by both Catholics and the Orthodox to be the "Founder of Monasticism", and Gautama Buddha, who, having abandoned his family for a solitary quest for spiritual enlightenment, ended up as the founder of Buddhism.
One interesting variation of the eremitic life is the Carthusian order of Roman Catholic monks and nuns. Carthusians live in what are essentially "communities of hermits", each monastic having their own cell (with sleeping chamber, study, and workshop) where they spend most of their time alone, except when they meet in church for worship, and on other occasions.
It is also possible for people to forsake human society for reasons other than religious. For example, Henry David Thoreau spent two years living an essentially solitary life near Walden Pond in pursuit of a simple, environmentally-friendly life. In a more notorious case, Theodore Kaczynski, known as the "Unabomber", lived in a remote cabin in Montana which gave him both refuge from what he viewed as a society corrupted by technology and privacy to build mailbombs.
Hermits in philosophy
Friedrich Nietzsche, in his influential work Thus Spoke Zarathustra, created the character of the hermit Zarathustra (named after the Zoroastrian prophet Zarathushtra), who emerges from seclusion to extol his philosophy to the rest of humanity.
Diogenes the Cynic, an ancient Greek philosopher, led an ascetic life in a barrel. According to legend, when Alexander the Great came to him one day and offered to grant him a wish, Diogenes asked Alexander to step out of his sunlight.