Regarding public "defection," I quote the immortal words of Inigo Montoya:
Meg, you continue to confuse two different things:
1. defection from the Catholic
faith2. defection from the Catholic
ChurchThose bolded words are important. Number 1 is a catch-all phrase referring to "apostasy, heresy, or schism." Number 2 is when a person makes a formal decision to renounce his membership in the Catholic Church.
You might think those two things mean exactly the same thing. They don't. Read
this docuмent to understand the canonical difference:
3. The juridical-administrative act of abandoning the Church does not per se constitute a formal act of defection as understood in the Code, given that there could still be the will to remain in the communion of the faith.
On the other hand, heresy (whether formal or material), schism and apostasy do not in themselves constitute a formal act of defection if they are not externally concretized and manifested to the ecclesiastical authority in the required manner.
If you read carefully, you will understand that while it is possible that a person who "defects from the Church" might also "defect from the faith," it is not necessary that these two things go together.
But a person who "defects from the faith" (through apostasy, heresy or schism), not a person who "defects from the Church," is the person discussed in Canon 184.