Naturopathic philosophy is based on the concept of the healing power of nature. The earliest doctors and healers worked with herbs, foods, water, fasting and bodywork. Certification follows study at a four-year, graduate-level, naturopathic medical school. This must include the basic sciences studied by M.D.s. Students are also taught holistic and nontoxic approaches to therapy with a strong emphasis on optimizing wellness and disease prevention. In addition to following a standard medical curriculum, the naturopathic physician is required to complete four years of training in clinical nutrition, acupuncture, homeopathic medicine, botanical medicine, psychology and counseling. Naturopathic physicians take professional board exams in order to be licensed by a state or jurisdiction as primary care general practice physicians (identified as an ND or NMD). For more information, see www.naturopathic.org and www.naturopathicassoc.ca.