Diminished responsibility (German Unzurechnungsfähigkeit, French non-imputabilité) is the absence, relevant in criminal law, of competency or soundness of mind in the perpetrator of a criminal act. Competency (also responsibility, capacity, German Zurechnungsfähigkeit, French imputabilité, more usually: imputation) became in 19th-century criminal theory the most important condition in subjective culpability and hence the key criterion i…