Objection & response

What qualifies as an “already condemned” heresy?

Canon 15's precondition, and the whole modern dispute in one question: must the heresy be named by an ecumenical council, or does patristic condemnation of its substance suffice?

The objection, at its strongest

No ecumenical council has ever condemned “ecumenism”, or most modern teachings, by name. Canon 15's precondition therefore fails, and any walling off built on it is unauthorized.

Why it is raised

Canonical precision matters; an elastic definition of “condemned heresy” would let anyone brand anything heresy and canonize every separation.

Evidence for the objection

The great condemnations name specific doctrines and persons; no pan-Orthodox synod has so named ecumenism.
The elasticity risk is real: history's parasynagogues all claimed a condemned heresy somewhere.

Evidence against it

The canon's own wording is “condemned by the holy Synods OR Fathers”, patristic condemnation suffices; it does not say “by an ecumenical council by name.”
The Church's practice with recurring heresy agrees: when Iconoclasm returned in 815, the confessors resisted at once on the strength of 787, no one demanded a new council to recondemn the same error under its new sponsors.
A teaching is condemned in its substance, not its label: whatever denies the Creed's “one holy catholic and apostolic Church” (as the branch theory does), or practises what named canons forbid (joint prayer, Apostolic 10, 45, 65; Laodicea 6, 33), stands under existing judgments.
St Nikodemos' canonical principle points the same way: the canons condemn the like case, not only the historical instance.

A limited conclusion

Disputed

On the canon's wording and the Church's practice, “already condemned” includes a teaching that renews in substance what Synods or Fathers condemned, the reading this library holds. What remains genuinely contested is the application: whether given modern acts and statements constitute such renewal, publicly and persistently. That is a question of fact and discernment, treated case by case, not settled by the definition alone.