I told you that “juvenile delinquent” is a contradiction in terms. “Delinquent” means “failing in duty.” But duty is an adult virtue — indeed a juvenile becomes an adult when, and only when, he acquires a knowledge of duty and embraces it as dearer than the self-love he was born with. There never was, there cannot be a “juvenile delinquent.” But for every juvenile criminal there are always one or more adult delinquents — people of mature years who either do not know their duty, or who, knowing it, fail.

Robert A. Heinlein (1907-1988) American writer

Starship Troopers, ch. 8 [Dubois] (1959)