Ahadith (or Hadith): A series of Muslim commentaries believed to have been taken directly from the words and actions of the Prophet Mohammed.

Ahimsa: Non-injury to all living things. Hindu monks, for instance, might sweep in front of them to avoid harming insects. Ahimsa may include a prohibition on emotional, as well as physical, harm. Popularized in the West by Mahatma Gandhi.

Animism: The belief, often found in pre-Christian religions, that a spiritual force is in all living creatures, and even in inanimate objects such as rocks or the wind.

The Bhagavadgita: The primary religious document of Hinduism. It uses a conversation between Lord Krishna and the hero Arjuna to reflect on how an individual should live his or her life. It calls for movement beyond ephemeral desire, beyond the self, into a permanent reality.

Brahman: In Hinduism, the central god or principle that stands behind all the divinities. The universal spirit; the original source of the cosmos.

Deep Ecology: The belief that animals and wild areas have value in themselves, and that human value cannot be separated from this, that we are all connected, part of the same web of life. Deep ecologists separate themselves from conventional, or "shallow," ecology, with its instrumental ideology that aims to conserve nature for long-term human use.

Dharma: The belief, in Hinduism and Buddhism, in a righteous path, way of living, and ethical system, largely found within oneself, through contemplation, rather than in the external world.

Ecological Footprint: The total amount of biological material used, and hence a rough measure of impact on the planet. Ecological footprints may be measured for a person, building, city, nation, or at any of a number of scales. Numerous ways of measuring ecological footprints have been devised.

Environmental Justice: The belief that environmental decisions are made in such a way that the poorest people suffer the most from environmental problems, and the fight for a fairer distribution of environmental burdens.

Gaia Hypothesis: The belief that the world is one enormous, living organism. From a rationalistic perspective, this is a metaphor for the intimate interconnections between ecosystems and the way a small change in one can have a big influence. From a spiritual perspective, all aspects may be filled with life-force, affecting each other in ways beyond material measurement.

Genesis: The first book of the Bible, crucial to both Jewish and Christian faiths. While the passage on human dominion over earth has been considered anti-environmentalist, much of Genesis portrays an awe-inspiring nature created by God.

Hadith: See Ahadith.

Halal: The Muslim dietary laws, which, among other things forbids the eating of pigs and mandates special methods, and a blessing, for other meat. Alcohol is also forbidden. Muslim authorities disagree as to whether eating Kosher food is permissible.

The Koran: (also transliterated from Arabic as the Quran and the Qur'an): The Muslim Holy Book, believed to be the word of Allah directly transmuted by the Angel Jibril to Mohammed, the final prophet. Such Christian and Jewish figures as Moses and Jesus are believed to be earlier prophets. The Arabic version of the Quran is considered perfect, with translations mere commentary. For many Muslims, The Quran is the central book from which all knowledge of truth, morality, science, and law is derived.

Kosher: The orthodox Jewish dietary laws, known as Kashrut, which forbids the eating of pigs and shellfish and mandates special methods for the slaughter of meat, and the separation of meat and milk, among other rules.

Millenarianism: The idea that human history, as currently experienced, may come to an end at any time, with a dramatic conflict between good an evil, Christ's return and a final rapture, or saving, of all Christian souls. A thousand year period of Christ's rule on earth will ensue.

New Age: A loosely organized spiritual movement, most popular in North America, that uses elements of many religions, with a strong animist bend. New Agers generally believe in mystical connections between events and people. Astrology, alternative medicine, the healing power of crystals, and channeling of the dead are some common New Age practices.

Pantheism: The belief that all things are aspects of a single god or spirituality, and that this god cannot be separated from the physical world. Pantheists believe that nature should be experienced with awe, and generally reject the idea of a personal God separate from the natural world.

The Quran: See the Koran.

Sangha: The Buddhist concept of a blessed community, often of monks or nuns.

Satyagraha: Mahatma Gandhi's philosophy of nonviolence as a self-purification combining the search for truth and the refusal to cause harm. Civil disobedience and passive resistance may be considered forms of satyagraha.

Sustainability: The belief, begun by modern environmentalists and social justice advocates, that all of society must work together to preserve the earth's resources and ecosystems. According to the Brundtland Declaration of 1987, "sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs."

Tahwid (or Tawhid): The oneness or unity of God, expressed as "there is no God but Allah" or "There is no God but God." Tahwid implies a strict social and moral structure based on belief in the Quran as God's final word.

The Torah: Depending upon context, either the Five Books of Moses or the entire Jewish Bible, believed to be the word of God. Including history, a set of laws centered in the Ten Commandments, and tales used as moral guidance, The Torah is the central document of Judaism from which all others proceed. Additional writings, primarily the Talmud, act as commentary on the Torah.