What is the Halachic protocol for assessing an alleged Apikores?

Question

Today, people cavalierly throw around accusations of Apikorsut to identify practically anyone who doesn't think the identical way as them. Throughout Jewish history, claims of Apikorsut have been behind some of the most vicious character assassinations of celebrated Jewish leaders.

An Apikores is legally defined by Rambam in Hilchot Teshuva 3:8 as:

שלשה הן הנקראים אפיקורסין: האומר שאין שם נבואה כלל ואין שם מדע שמגיע מהבורא ללב בני האדם, והמכחיש נבואתו של משה רבינו, והאומר שאין הבורא יודע מעשה בני האדם. כל אחד משלשה אלו הן אפיקורוסים.

"There are three that are called "heretics" (apikorsin): One who says that there is no such thing as prophecy and there is no such thing as information that is passed from the Creator to the heart of man. And one who denies the prophecy of Moses, our teacher. And one who says that the Creator does not know man's actions. Any one of these is considered an "apikores" - heretic."

Suppose that a reliable person informs you that someone with an otherwise perfect חזקת כשרות has been "teaching Apikorsut". Do we immediately accept the claim and distance ourselves from that person (or even hate them), or is there some process via which the accused's status can be ascertained? And would the process be any different if we had an active Sanhedrin which was accepted by all of Yisrael?

What if there is no way to verify for sure if he had actually taught Apikorsut at any point, and he himself insists that he is committed to these principles as codified by Rambam? Does his own word carry any weight?

Answer 1

As far as intial acceptance of a report heard from an individual is concerned, Chofetz Chaim differentiates between intellectually accepting something to be true vs. taking steps to protect oneself while at the same time not accepting it to be true at all:

אַף עַל פִּי שֶׁבֵּרַרְנוּ, דְּקַבָּלַת לָשׁוֹן הָרָע, דְּהַיְנוּ לְהַחְלִיט בְּלִבּוֹ שֶׁהַדָּבָר אֱמֶת, אָסוּר מִן הַתּוֹרָה, מִכָּל מָקוֹם אָמְרוּ חֲזַ"ל, דְּלָחוּשׁ מִיהוּ בָּעֵי {שלחשוש אמנם צריך}. וּבֵאוּר הַדָּבָר, דְּצָּרִיךְ לְקַּבֵּל אֶת הַדָּבָר בְּדֶרֶךְ חֲשָׁשׁ בְּעָלְמָא, הַיְנוּ רַק כְּדֵי לִשְׁמֹר אֶת עַצְמוֹ מִמֶּנּוּ שֶׁלֹּא יַגִּיעַ לוֹ הֶזֵּק עַל יָדוֹ, וְלֹא יִהְיֶה זֶה הַדָּבָר אֲפִלּוּ בְּגֶדֶר סָפֵק דְּמַעֲמִידִין לְאָדָם בְּחֶזְקַת כַּשְׁרוּת, וְלָכֵן מְחֻיָּב עֲדַיִן לְהֵיטִיב עִם הַנִּדּוֹן בְּכָל הַטּוֹבוֹת, שֶׁצִּוְּתָה הַתּוֹרָה, לִשְׁאָר אֲנָשִׁים מְיִּשְׂרָאֵל, כִּי לֹא נִגְרַע עֶרְכּוֹ בְּעֵינֵינוּ על יְדֵי הַלִּישָׁנָא בִּישָׁא {הלשה"ר} לְשׁוּם דָּבָר*, רַק שֶׁהַתּוֹרָה הִתִּירָה לָחוּשׁ לַלִּישָׁנָא בִּישָׁא לְעִנְיַן לִשְׁמֹר אֶת עַצְּמוֹ וְאֶת אֲחֵרִים מִמֶּנּוּ

Even though we explained that acceptance of lashon hara — that is, to believe in one's heart that the thing is true — is forbidden according to the Torah, still, Chazal have said (Niddah 61a): "One must, nevertheless, suspect." That is, one must accept the thing on the level of suspicion alone, to guard himself from him [the object of the lashon hara] so that no harm come to him at his hand. And let there be no doubt about the fact that a man is assumed to be kosher [unless proven otherwise]. And so he [the hearer] is still obligated to grant him [the one spoken about] all the good commanded by the Torah [to be accorded] to all the men of Israel. For his worth has not been diminished in our eyes in any way because of this lashon hara. But the Torah has allowed us to be suspicious on the basis of the lashon hara to the extent of guarding ourselves and others from him. (Sefaria)

So in your case, there would be no justification for hating the person in question, or even for accepting it intellectually to be true (or even to have doubts about it). But one may take practical steps to protect oneself from potential harm. It's a delicate balance, because even when taking those steps one cannot accept the report in his heart at all.

As far as ascertaining their status is concerned, the Chofetz Chaim writes further that a person can lose his חזקת כשרות (and, he adds in Be'er Mayim Chaim, be יוצא מכלל עמיתך) if it has been public knowledge on many occasions that he unapologetically committed a well-known transgression. However, there are some important qualifications: in a footnote of the Be'er Mayim Chaim (same author) he expresses doubt as to whether one such occasion is enough, and also writes that if he has enemies in that city that may have started the rumor, it is not to be believed. He further qualifies that if the rumor was started by one individual it cannot be believed.