From Wikipedia, the free encyclopedia.
The term compos mentis comes from Latin, compos meaning "in control," and mentis, genitive singular of mens, mind. and means having a sound mind; to be sane.
This is most typically used in its opposite form, non compos mentis, that is, not having control of one's faculties, as in a phrase such as "It was determined that the criminal was non compos mentis" (i.e., insane); one might say the criminal was compos mentis, i.e., the criminal had full knowledge of his/her acts and is competent to stand trial.
It is typically a legal term.
