“Within these limits the almost invisible and tremulous ball of orthodoxy was allowed securely to vibrate. On either side, beyond this consecrated ground, the heretics and dæmons lurked in ambush to surprise and devour the unhappy wanderer. But as the degrees of theological hatred depend on the spirit of war, rather than on the importance of the controversy, the heretics who degraded, were treated with more severity than those who annihilated, the person of the Son. The life of Athanasius was consumed in irreconcileable opposition to the impious madness of the Arians; but he defended above twenty years the Sabellianism of Marcellus of Ancyra; and when at last he was compelled to withdraw himself from his communion, he continued to mention, with an ambiguous smile, the venal errors of his respectable friend.”

(Edward Gibbon, The Decline and Fall of the Roman Empire, vol. II, chapter XXI; p. 783 in volume 1 of the Penguin edition.)