 A crucial point is that Fârâbî is worried not just about lexical confusions (confusions between two meanings of a term or between two similar terms), but about confusions arising from the misleading grammatical form of a term: he thinks that these confusions have given rise to serious philosophical errors, and he thinks that the translation process has made such confusions more likely. Part I of the Book of Letters distinguishes between the primitive terms of a language and the terms derived or “paronymous” [mushtaqq] from them. Fârâbî takes the notion of paronymy ultimately from Aristotle’s Categories 1 (1a12–15). A proper noun like “Socrates”, a common noun like “horse”, and an abstract accidental term like “whiteness” are all primitive terms, but the concrete accidental term “white” is paronymous or derived from “whiteness”, not necessarily in the sense that it arises later in the history of the language than “whiteness”, but in the sense that something is called “white” (rather than “whiteness”) because there is a whiteness in it. Fârâbî, unlike Aristotle, also treats (finite) verbs as being paronymous from their infinitives, where the infinitive [maṣdar] in Arabic is a noun expressing the action of the verb. The grammatical form of a paronymous term suggests that something is X by having an X-ness present in it, or V’s by having an action of V-ing in it. But sometimes the grammatical form of a term misleadingly fails to track its logical form, and in these cases there is a risk of being deceived by what Aristotle in On Sophistical Refutations calls sophisms of skhêma tês lexeôs: this is usually translated into English as “sophisms of figure of speech”, but they would more accurately be called “sophisms of grammatical form”, i.e., sophisms which arise because the grammatical form of an expression fails to correspond to its logical form, and which can be solved only by diagnosing this  discrepancy.[17]  The Arabic translators of Greek philosophical texts, in trying to find Arabic equivalents for the Greek source-terms, often use such awkward and potentially misleading expressions, and so do Arabic philosophical texts written in imitation of the language of the translations. In particular, Fârâbî says that the Greek word for “being” was non-paronymous, but that some translators, not finding a good non-paronymous Arabic equivalent, instead used the paronymous word, “mawjûd”, literally “found”, and that this gave rise to the grammatical appearance that something is existent or “found” [mawjûd] through an existence or “finding” [wujûd] present in it, as something is white through a whiteness present in it. Fârâbî, applying a methodological principle of charity, seems to assume that in each case the Greek original was free of such infelicities: this means that, in practice, his reconstructed Greek serves as an ideal logical language, i.e., a language in which grammatical form always tracks logical form.