Fr. Seraphim Rose, though against Orthodox participation in the ecumenical movement, in his later years, reacted strongly against Orthodox who over-reacted in their condemnation of fellow-Orthodox for attending ecumenical gatherings by calling them "heretics". He clearly articulated his thoughts in his "Defense of Fr. Dimitry Dudko" (p. 130), where he wrote:
"Ecumenism is a heresy only if it actually involves the denial that Orthodoxy is the true Church of Christ. A few of the Orthodox leaders of the ecumenical movement have gone this far; but most Orthodox participants in the ecumenical movement have not said this much; and a few (such as the late Fr. Georges Florovsky) have only irritated the Protestants in the ecumenical movement by frequently stating at ecumenical gatherings that Orthodoxy is the Church of Christ. One must certainly criticize the participation of even these latter persons in the ecumenical movement, which at its best is misleading and vague about the nature of Christ's Church; but one cannot call such people 'heretics', nor can one affirm that any but a few Orthodox representatives have actually taught ecumenism as heresy. The battle for true Orthodoxy in our times is not aided by such exaggerations."