Strictly speaking though, you know what a formal heretic is. It's when the Church tries and formally convicts someone of heresy, which also involves an excommunication. Like we saw with Martin Luther.
Formal heretic doesn't mean "actual heretic", "provable heretic", "heretic in reality", "heretic based on provable facts and air-tight logic" or any of those things. It is exclusively when the Church FORMALLY declares someone to be a heretic.
That's the problem.
We have enough to go on to be Trad (aloof from this destroyer and his counterfeit church) but not enough to compel anyone's conscience. If it were simpler than that, then the Crisis in the Church wouldn't be in its 51st year (assuming a start date of April 1969, when the Novus Ordo was promulgated).
This is false. Formal heresy is not determined by a conviction in an ecclesiastical court.
From Canon Law (A Text and Commentary) by Bouscaren and Ellis (p. 898):
"
Apostasy, Heresy, Schism. All apostates from the Christian faith, and all heretics and schismatics: (1) are
ipso facto excommunicated; (2) if after due warning they fail to amend, they are to be deprived of any benefice, dignity, pension, office, or other position which they may have in the Church, they are to be declared infamous, and clerics after a repetition of the warning are to be deposed; (3) if they have joined a non-Catholic sect or publicly adhered to it, they are
ipso facto infamous, and clerics, in addition to being considered to have tacitly renounced any office they may hold, according to canon 188.4, are, if previous warning proves fruitless, to be degraded (c. 2314, S 1)."
Ibid, p. 938:
"c.
Pertinaciter (in definition of heretic) does not imply duration, nor violence; it simply means setting up one's own mind against the
known mind of the Church. The denial must be externally manifested, and
formal, i.e., subjectively a grave sin."
As you can see, a trial is not necessary to establish formal heresy. In fact, manifest heresy implies formal heresy. It is impossible for a manifest heretic to not at the same time be a formal heretic. And all manifest heretic means is that the person has made his opposition to some doctrine of the Catholic faith sufficiently known to others so that there can be no reasonable doubt that the crime has been committed.
Manifest heresy isn't like other crimes such as stealing or murder. You could possibly conceal a theft. But you can't conceal manifest heresy. By definition it is a public act. It is possible that many people don't recognize it as a crime. But that doesn't have any effect on the objective fact that the crime did occur. A heretic isn't excused if everyone agrees with him or worse (in my opinion) simply denies that there is any punishment due for such a crime.