A disease is any condition which results in the disorder of a structure or function in a living organism that is not due to any external injury. The study of disease is called pathology, which includes the study of cause. Disease is often construed as a medical condition associated with specific symptoms and signs. It may be caused by external factors such as pathogens or by internal dysfunctions, particularly of the immune system, such as an immunodeficiency, or by a hypersensitivity, including allergies and autoimmunity.
Disease is an experience of mortal mind. It is fear made manifest on the body. Divine Science takes away this physical sense of discord, just as it removes a sense of moral or mental inharmony.
Mary Baker Eddy, Science and Health, Chapter XIV. 20.
