It wasn't until 1925 that Ontario recognized naturopathic medicine under the Drugless Practitioners Act. Today, there is a wide variety of conditions that naturopathic doctors treat, including: acute conditions such as sore headache, chronic illnesses such as musculoskeletal pain and mental and emotional problems of anger or depression. Naturopathic practice is centered on the basis that living organisms are essential to healing. Naturopathic medicine calls this fundamental principle vis medicatrix naturae, recognizing the body's innate ability to heal itself. The next principle concerns health restoration that any intervention used should not further disturb a system trying to recover. This is expressed as primum non nocere, the authority to choose interventions that cause the least harm. Therefore, to remove the cause of the disease (tolle causum), the treatment of the whole person must be considered. The doctor therefore becomes the teacher (docere) who educates and supports the management of patients' health. Naturopathic medicine ascribes to a therapeutic hierarchy that integrates the entire spectrum of modern biomedicine in a continuum that includes mental, emotional and spiritual.