Some definitions: Etiology (from Greek: aitia (cause) and logos (science) and late Latin) is that part of medical science that deals with the causes of disease. All diseases have predisposing and direct causes, the former setting the scene in which the latter is more likely to have an effect. Predisposition is always, to some extent, inherited; it is often a complex societal, cultural and environmental amalgam. For example, inheritance of a propensity to alcoholism, coupled with drunkenness, and the impairment of judgement and manual dexterity which follows, leads to a road traffic accident: trauma is the direct cause of the injuries sustained. Inheritance of the multiple polyposis coli gene increases the risk of colon cancer, but the more proximate causes related to diet are still influential.