Autoaggression and autoimmune attack are established vernacular in the literature of autoimmune disease, and reflect the popular view that autoimmunity is a disease of immune dysregulation in which the immune system inappropriately attacks healthy tissue. The aim of this article is to focus attention on an alternative, indeed opposite, view—that autoimmunity represents the response to a primary lesion in the target tissue, rather than its cause, and that like alloimmunity, autoimmunity is physiological, appropriate and protective. The cell death and tissue damage which results is characteristic of an immune response programmed to eliminate immunogen, remove detritus and isolate the lesion.