Voluntary Simplicity or simple living is a lifestyle sometimes but not necessarily associated with civil disobedience and with environmental sustainability.
Voluntary Simplicity involves choosing a lifestyle that was common to premodern humanity, when people generally lived in subsistence economies that valued community survival and wellbeing over individual profits and escapist entertainment.
Voluntary Simplicity may involve reducing desires for more new things that are constantly developed and promoted by modern consumer society.
Commitments to voluntary simplicity may be self-centered in terms of making oneself independent from social pressures, but such commitments may be altruistic or charitable in that desires for power and material goods often require competitive exploitation and degradation of other people.
Sources for a simpler lifestyle may be religious, philosophical, or economic.
A familiar religious community that maintains a simple lifestyle in resistance to modernity is the Amish. Other such groups have included Shakers, Mennonites, traditional Quakers, Buddhists, some Hindu traditions, and Sufi Islam. Religious practices of mortification may be associated.
Voluntary simplicity may also be political and economic (not automatically excluding religion). Mahatma Gandhi, Independence leader and Prime Minister of India, led a life of extreme simplicity including hunger strikes, and he wanted India's economic development to return to village life instead of urbanization and modernization.
Henry David Thoreau's Walden (1850) is an American literary classic describing one man's efforts to detach himself from the busy-ness of modern American life by living alone in a self-built cabin by Walden Pond.
Possible recent cultural manifestations of Voluntary Simplicity:
Back to Basics: Living with "Voluntary Simplicity" (from Oprah.com)
Simple Human consumer site