The historical debate between Mattā ibn Yūnus and Abū Saʿīd al-Sīrāfī, as reported in Abū Ḥayyān al-Tawḥīdī’s al-Imtāʿ wa-l-Muʾānasa, is among the earliest and most fundamental discussions of the relation between language (grammar, naḥw), reason (logic, manṭiq), and truth. Because it concerns distinguishing the correct from the incorrect, it may be counted among the earliest discussions in the philosophy of language. Emphasizing the generality and universality of meanings, Mattā ibn Yūnus regards logic as the path to truth, shared among peoples and communicable through translation. By contrast, al-Sīrāfī stresses grammar and linguistic usage, highlighting natural language’s role in understanding meaning and accessing truth. Aware of this debate, al-Fārābī seeks to reconcile the unity of rational meaning and logical truth with the plurality of peoples, cities, languages, and cultural orders (milal). For him, human nature requires that, within civic life, human beings use gestures, vocal sounds, and words according to their needs. Thus language begins with gesture, proceeds through sounds and syllables to the institution of words and their combinations, and continues to the emergence of practical and theoretical arts: rhetoric, poetry, dialectic, sophistry, and demonstration. These arts are means for knowing causes and attaining the practical and theoretical ends of the city. Here, the rational-discursive faculty (nuṭq), as the specific form of the human being, gradually manifests itself through the perfection of the city and its cultural order (milla), from sense perception to thought and demonstrative language, becoming the genuine basis for defining the human being and true happiness.