The English word Asceticism comes from the Greek: άσκησις, áskēsis, meaning "exercise" or "training". Originally it was athletes who were said to go through ascetic training, and consequently, to be ascetics. Since it is a short metaphorical leap from the athletic to the spiritual, the word came to be used in the spiritual sense. Prechristian writers speak of the "askesis" of the soul or of virtue—the discipline of the soul, or the exercise in virtue. We see in this word the notion of training to achieve the desired result but, as with many things, the tool can become confused with the result.

Today our word asceticism usually describes a lifestyle characterized by abstinence from various sorts of worldly pleasures often with the aim of pursuing religious and spiritual goals. Just what those goals are varies by tradition. There are some who use the word to refer to practices such as fasting, even if they are not a matter of life style. In this usage monasticism is the lifestyle of asceticism but there may be ascetic practices that are used in spiritual training by those who are not monks. At any rate the physical idea, no less than the spiritual, underlies the meaning of the term especially in medieval Christian parlance. It was in medieval times when monasticism flourished in the Christian west.

The aim, as this section develops, is to contrast the goals of different ascetic traditions within Christianity and those from other religions. When looking from the outside matters of ceremony and practice can seem the same and I am claiming that if you take the trouble to look deeper you will find differences. Take as an example meditation. As an introduction to this line of thinking I borrow the following: 

It is unfortunate that there is widespread confusion, not to mention delusion, ... whereby the Jesus Prayer is thought to be equivalent to yoga in Buddhism, or 'transcendental meditation', and other such Eastern exotica. Any similarity, however, is mostly external, and any inner convergence does not rise beyond the natural 'anatomy' of the human soul. The fundamental difference between Christianity and other beliefs and practices lies in the fact that the Jesus Prayer is based on the revelation of the One true living and personal God as Holy Trinity No other path admits any possibility of a living relationship between God and the person who prays.

 

Eastern [non-Christian] asceticism aims at divesting the mind of all that is relative and transitory, so that man may identify with the impersonal Absolute. This Absolute is believed to be man's original 'nature', which suffered degradation and degeneration by entering a multiform and ever-changing earth-bound life. Ascetic practice like this is, above all, centred upon the self, and is totally dependent on man's will. Its intellectual character betrays the fullness of human nature, in that it takes no account of the heart. Man's main struggle is to return to the anonymous Supra-personal Absolute and to be dissolved in it. He must therefore aspire to efface the soul (Atman) in order to be one with this anonymous ocean of the Suprapersonal Absolute, and in this lies its basically negative purpose. 

 

... Eastern styles of contemplation, ...do not claim to be the contemplation of God, and are in fact man's contemplation of himself. This does not go beyond the boundaries of created being, nor does it draw anywhere near to the Truth of primordial Being, to the uncreated living God Who has revealed Himself to man. This kind of practice may well afford some relaxation or sharpen man's psychological and intellectual functions, yet 'that which is born of the flesh is flesh' (John 3:6) and 'they that are in the flesh cannot please God' (Rom. 8:8). orthodoxinfo.com

While there are Christian monastic orders to this day, monasticism in Christianity was something of a late arrival; the truly monastic Christian tradition began in the Christian East with the Desert Fathers around the middle of the third century. The writings of John Cassian, one of their number, are thought to be largely responsible for bringing monasticism to the Christian West. In Medieval (476-1500) Europe, the rise of Christian monasticism was, in part, a search for a purer Christianity. This was also the time of the Imperial Church where many things from outside of Christianity were being added to Christian observance. The Roman Empire was also falling apart. The general turmoil of the times caused many to retreat to monasteries just as the desert fathers retreated to the desert to flee the persecution of Rome. There are many formal monastic orders in the West, but really only one in the East.

In Judaism there are ascetic practices (like fasting) but not a large tradition of asceticism as a life-style. It is often claimed the first-century Essenes were a monastic group but that is widely thought today to be an overlay from the Christian monastics who began to study them. The Medieval Ḥasidim are noted for their rigorous observance of the Law and ritual, the Cabalists for their secret societies, or at least lent their name to such, were both in the context of non-Jewish even hostile governments.  

According to what I have read to date, monasticism has no home in Islam. Having said that, Zuhd in Arabic, encompasses both the Islamic concept of asceticism and more specifically the concept of renunciation. Asceticism involves a life of privation that lacks certain comforts and luxuries and early ascetics were often characterized by their poverty. Renunciation involves detachment and an indifference towards worldly items. Both of these concepts require one to shun a life of luxury in favor of a more pious and simple life. Zuhd requires the renunciation of not only that which is prohibited but also that which is lawful. According to Al-Qushayri, a tenth century Islamic Philosopher, it is an obligation to renounce that which is prohibited but to renounce that which is lawful constitutes a virtue. Renunciation consists of two distinct interpretations. The first is external, which involves the renunciation of lavish clothing, food, comfort, sleep, accommodations, and human relationships. The second is internal, which involves the renunciation of intentions and desires. These two interpretations are often combined and used interchangeably when defining zuhd. In Islam, zuhd is often attributed to Sufism and the mystics but the term is also used among common believers and is a tool for religious and spiritual development. The concept of zuhd enables one to perceive the greater importance of the spiritual over the physical.

When I was at university I had a friend who separated religions into two categories: Life Affirming and Life Denying. She put Christianity, into the former and the rest of world religions in the latter. This distinction seems more at home in the philosophy of Nietzsche than in the present discussion but it serves as a pivot point for this discussion. (Although citing a brief conversation with an unnamed Sociology undergrad is not academically acceptable.) A Rabbi told me once that "for the Jew life is lived." Rabbis are puzzling folks but his point was that "life is a gift from G-d and it should be lived to the fullest, although you can't get crazy." This sort of moderation (not getting crazy) is the common position of especially the protestant Christian traditions.

The Indian (Dharmic) religions (including yoga) have as their main goal liberation from the body. There is a process of mind-body transformation effected by exercising restraint with respect to actions of body, speech, and mind. The founders and earliest practitioners of these religions Hinduism, Jainism and Buddhism lived extremely austere lifestyles, refraining from sensual pleasures and the accumulation of material wealth. The friendly explanation is that this is not an eschewal of the enjoyment of life, rather a recognition that spiritual and religious goals are impeded by such indulgence. The other, perhaps more common explanation is that goal of the Dharmic religions generally is to finally escape the cycle of reincarnation. This is accomplished by living as pure a life as possible in this life. The monastic life is thought by many to aid in this.

Taoism doesn't make a rigid division between body and spirit; it recognizes that physical actions have a spiritual effect. Taoist practices center around energy flow (ch'i or often qi). There are Taoist Monks and they are often practitioners of martial arts.

http://en.wikipedia.org/wiki/Asceticism  7/8/11

http://www.thefreedictionary.com/asceticism  7/8/11

http://www.bbc.co.uk/religion/religions/taoism/practices/physical.shtml  3/17/13

http://orthodoxinfo.com/praxis/buddhism-and-eastern-asceticism-compared-to-orthodox-christian-asceticism.aspx 11/17/15

https://en.wikipedia.org/wiki/Asceticism_in_Judaism 11/17/15

https://en.wikipedia.org/wiki/Monasticism 12/21/15

https://en.wikipedia.org/wiki/Zuhd_in_Islam 12/21/15