"Traditionally, insanity, craziness or madness is the behavior whereby a person flouts societal norms and may become a danger to themselves and others. Greek tragedies and Shakespeare often refer to madness in this sense. Psychologically, it is a general, popular and legal term defining behavior influenced by mental instability. In modern usage, it is most commonly encountered as an informal, unscientific term, or in the narrow legal context of the insanity defense. In the medical profession the term is now avoided in favor of more specific diagnoses of mental illness such as schizophrenia and other psychotic disorders.[1] When discussing mental illness in general terms, "psychopathology" is also considered a preferred descriptor.[2]
In English, the word "sane" derives from the Latin adjective sanus meaning healthy. The phrase "mens sana in corpore sano" is often translated to mean a "healthy mind in a healthy body". From this perspective, insanity can be considered as poor health of the mind, not necessarily of the brain as an organ (although that can affect mental health), but rather refers to defective function of mental processes such as reasoning. A Latin phrase for "sane" is "compos mentis" (lit. "of composed mind"), and a euphemistic term for insanity is "non compos mentis". In law, mens rea means having had criminal intent, or a guilty mind, when the act (actus reus) was committed."