A Topic of Moral Theology
Apostasy from religion (Can. 2385)
Who is an apostate from religion (Can. 644).
In the index as Abortion · Apostasy · Religious
In the manuals
A Manual of Moral Theology for English-Speaking Countries
Vol. II, Bk. X, Pt. III, Ch. I, D.—Excommunications Reserved to the Ordinary, nn. 14 & 15 (2 passages — hover a number to read it)
Treated under the broader heading Excommunications Reserved to the Ordinary — Noldin, Summa of Moral Theology · Wouters, Manual of Moral Theology · Gury-Ballerini, Compendium of Moral Theology (8th ed., 1884) · Tanquerey · Marc, Institutiones Morales · Konings, Theologia Moralis · The Casuist — these works do not divide the matter as finely as we do here, so their treatment stands one heading up (ed.)