More From the Matter [of the Importance of Silence, That was] Discussed [in Chapter 1]
[In addition to the previous explanation offered, as to why the attribute of silence] is referred to as a trade, we can also [provide the following explanation]: Each trade requires learning, to the point that one masters that trade. The same [concept] is true [with respect to] the matter of speech: A person can’t say, “What is the reason for me to bring myself to toil in the matter of “Shmiras HaLashon” – “Guarding One’s Tongue”, [in order] to know all of its ways? [Instead], I will acquire a natural means for myself [by which to avoid speaking that which is forbidden by], constantly acting like a mute, and this will be sufficient for me [to avoid forbidden speech]!” [A person should not think that it is sufficient to constantly remain silent in order to avoid involvement in forbidden speech], for this is not true of the matter [of avoidance of forbidden speech], as [one’s response to such types of speech], varies extensively based on the [specific] situation that one finds himself in. (This is explained in sefer “Chofetz Chaim”, in volume 1, in klal 8, sif 5, and in a number of places in volume 2 [of sefer “Chofetz Chaim”]). Therefore, it is necessary for one to know the matter of [permitted and forbidden] speech, in its generalities and in its specifics, and [only] then will one know how to act in this “trade” of silence.
 The passage referred to from sefer “Chofetz Chaim” discusses the types of people regarding whom it is permitted and is a mitzvah to shame and deride. Based on this teaching, we can understand the unfortunate circumstance of one who simply is determined to constantly remain silent. For when someone should be derided for opposing the Torah, this person will remain silent, thus passively avoiding the mitzvah of coming to the defense of the Torah.
The passage from sefer “Chofetz Chaim” states as follows:
“This entire prohibition against Lashon HaRa applies specifically to a person, who, based on the Torah law, is still within the category of “amitecha” – “your nation”, meaning, he is with you, [as part of your nation], by being with you in [observance of] Torah and mitzvos. However, those people, who you recognize as having apikorsus within them, it is a mitzvah to shame them and scorn them, whether in their presence or not in their presence, in any matter that he sees or hears about them, as it is written, “A person should not oppress [with his words], one among his nation…” (Vayikra: 25; 17), and, “Do not be a talebearer in your nation…” (Vayikra: 19; 16) [However, these people who reject the Torah and the mitzvos] are not included in this category [of people that the pesukim refer to], for they do not perform the actions of your nation [that are distinct from the rest of the world]. The [pasuk from Tehillim] says [about such people]: “Do I not hate the enemies of HaShem, and I quarrel with those who rise up against You?” (Tehillim: 139; 21) An “apikorus” is defined as one who denies the Torah and [denies] prophecy from [among the People of] Israel, whether [they deny the veracity] of the Written Torah or of the Oral Torah. [One is an “apikorus”] even if he says that the entire Torah is from Heaven, with the exception of one pasuk, or [with the exception of one kal vachomer, or one g’zeirah shavah, or one dikduk.” (See Sanhedrin, 99a)
Kal Vachomer is an a fortiori argument.
G’zeirah Shavah is a method of exegesis whereby the presence of a particular word or word-root indicates similar legal characteristics to a precedent case where the same word or word-root is used.
Dikduk is the modification to a word-root that indicates a word’s grammatical characteristics.