It would seem that zeal is not an effect of love. For zeal is a beginning of contention. — Thomas Aquinas
There’s a guy who won’t be in contention. There’s another one I don’t have to worry about. — Jack Nicklaus
Whoever keeps an open ear For tattlers will be sure to hear The trumpet of contention. — William Cowper
Obstinacy and contention are common qualities, most appearing in, and best becoming, — Michel de Montaigne