Eustathius is described as a man unstable in doctrine, vacillating from party to party, subscribing readily to Creeds of various tendency, yet commanding the respect even of his enemies by a life of extraordinary holiness, in which active benevolence was combined with extreme austerity.  “He was a man,” says Mr. Gwatkin The Arian Controversy, p. 135., “too active to be ignored, too unstable to be trusted, too famous for ascetic piety to be lightly made an open enemy.”