The word "刚愎自用" is formed by combining four characters: "刚" meaning stubborn or rigid, and "愎" meaning obstinate or perverse, together intensifying the sense of inflexibility; "自" means self, and "用" means to use or employ, so "自用" conveys acting on one's own ideas. The entire phrase thus literally constructs the meaning of being headstrong and insisting on one's own ways without heeding others.