 Al-Fārābī clearly believes that mismatches between words and concepts are a bad thing, but it’s less clear why he believes this, or what he thinks should be done about it. The original matching was set up by an artless consensus of the community, presumably because it served some social purpose. Al-Fārābī never analyses in detail what this purpose might be, or, for example, how it would be damaged by using derived words for underived concepts. Does he really fear that a mismatch could lead to a breakdown in communication, even if the whole community adopts the mismatch? Germann (2015/6: 138f) has suggested that his fear is more specific: he worries that if mismatches develop, teachers—including philosophy teachers—may be unable to pass information reliably to their students. 