The courtesy of communication using shared language is a gift, that we give and receive — we make and allow for common assumptions that underlie normal human communication. In peaceful and voluntary interchange, this is a courtesy that we mutually extend to one another cooperatively.
For example, in a situation where two or people extend each other human dignity, there is no need to pretend to not understand what the other person is saying, when they formulate noises with their mouths that sound like words that are intelligible in a language that you know, that you assume the other person knows, mutually.
However, when a human being sets aside their humanity and acts like a brute/animal/beast to another human being, coercively and violently, that person can no longer be assumed to be acting as a natural human. Under such a situation of coercion, the courtesy of mutually intelligible language need no longer be extended or deservedly taken for granted. This is akin to how one does not attempt to reason intelligibly with a rabid dog (or, for that matter, even with a perfectly docile pet dog.)
In the usual course of human affairs, we all interact with each other voluntarily/anarchically, i.e. without coercion or compulsion, i.e. without threat from either side of loss of life or property. We are governed only by this singular requirement of natural law, as it pertains to the duty we hold, one to all. In this usual course of interchange and interaction, human are said to be acting cooperatively, which is logically consistent with the equal dignity of each human being, by virtue of sharing the same nature.
This usual anarchic/voluntary course of interaction is first broken, by definition, by the first non-cooperator. And, most usually, the breaking of this peaceful interaction is precipitated directly by the agents of the State, or by other actors who act on behalf of the State's aims (inadvertently or otherwise).