Reason is the only means of communication among men, and an objectively perceivable reality is their only common frame of reference; when these are invalidated (i.e., held to be irrelevant) in the field of morality, force becomes men’s only way of dealing with one another.
Concepts and, therefore, language are primarily a tool of cognition — not of communication, as is usually assumed. Communication is merely the consequence, not the cause nor the primary purpose of concept-formation — a crucial consequence, of invaluable importance to men, but still only a consequence. Cognition precedes communication; the necessary precondition of communication is that one have something to communicate. (This is true even of communication among animals, or of communication by grunts and growls among inarticulate men, let alone of communication by means of so complex and exacting a tool as language.)