Asceticism (/əˈsɛtɪsɪzəm/; from the Greek: áskesis, "exercise" or "training") is a lifestyle characterized by abstinence from worldly pleasures, often for the purpose of pursuing spiritual goals. Ascetics may withdraw from the world for their practices or continue to be part of their society, but typically adopt a frugal lifestyle, characterised by the renunciation of material possessions and physical pleasures, and time spent fasting while concentrating on the practice of religion or reflection upon spiritual matters.
Asceticism is classified into two types. "Natural asceticism" consists of a lifestyle where material aspects of life are reduced to utmost simplicity and a minimum but without maiming the body or harsher austerities that make the body suffer, while "unnatural asceticism" is defined as a practice that involves body mortification and self infliction of pain such as by sleeping on a bed of nails.
Asceticism has been historically observed in many religious traditions, including Buddhism, Christianity, Hinduism, Jainism and Judaism. Mainstream Islam has lacked asceticism, except for its minority Sufi sect whose long tradition has included strict asceticism. The practitioners of these religions eschewed worldly pleasures and led an abstinent lifestyle, in the pursuit of redemption,salvation or spirituality. Asceticism is seen in the ancient theologies as a journey towards spiritual transformation, where the simple is sufficient, the bliss is within, the frugal is plenty.
The adjective "ascetic" derives from the ancient Greek term askēsis, which means training or exercise. The original usage did not refer to self-denial, but to the physical training required for athletic events. Its usage later extended to rigorous practices that are used in all major religious traditions, in varying degrees to attain redemption and higher spirituality.