 Once the idea has become established that words signify meanings, the community will aim to develop the language so that words imitate the “ordering” or “regime” (intiẓām) of the primary concepts ([Letters] (122) 139.2–4). This regime includes any relationships that the concepts have as concepts. For example, two concepts may be similar; so an effort will be made to find a pair of similar words to express these concepts. Al-Fārābī notes that this effort may misfire and result in homonymy—a single word being used for two different concepts ([Letters] (124) 140.8–10). The pressure to copy similarities also leads to metaphors ([Letters] (127) 141.10).