Al-Farabi also wrote a commentary on Aristotle 's work, and one of his most notable works is Ara Ahl al-Madina al-Fadila, where he theorized an ideal state, supposedly modelled on Plato's The Republic. Al-Farabi argued that religion rendered truth through symbols and persuasion, and, like Plato, saw it as the duty of the philosopher to provide guidance to the state. Al-Farabi incorporated the Platonic view, drawing a parallel from within the Islamic context, in that he regarded the ideal state to be ruled by the Prophet - Imam, instead of the philosopher-king envisaged by Plato. Al-Farabi argued that the ideal state was the city-state of Medina when it was governed by Muhammad as its head of state, as he was in direct communion with Allah whose law was revealed to him. In the absence of the Prophet-Imam, al-Farabi considered democracy as the closest to the ideal state, regarding the order of the Sunni Rashidun Caliphate as an example of such a republican order within early Muslim history. However, he also maintained that it was from democracy that imperfect states emerged, noting how the order of the early Islamic Caliphate of the Rashidun caliphs, which he viewed as republican, was later replaced by a form of government resembling a monarchy under the Umayyad and Abbasid dynasties.