In the 8th century Ibn al-Muqaffaʿ wrote his book about the instructions for the ruler, the Kitāb al-Ādāb al-kabīr. Central themes are friendship, prudence, justice and moderation; knowledge and reason are cornerstones, which explicitly do not exclude the values of religion. We detect central concepts of Aristotle’s Nicomachean Ethics. At the same time, in comparison with the letters by his contemporary ʿAbd al-Ḥamīd al-Kātib, with the apocryphal exchange of letters between Aristotle and Alexander in the translation by his contemporary Sālim Abū l-ʿAlāʾ, with the letter of the Zoroastrian priest Tansar/Tosar and with parallels in the Zoroastrian encyclopaedia Dēnkard Ibn al-Muqaffaʿ turns out to be a representative of Iranian-Sassanian traditions of the mirror of princes including their Greek sources, and of Islamic parenetic literature, as reflected in his contemporary Ṣāliḥ b. ʿAbd al-Quddūs. Ibn al-Muqaffaʿ’s Kitāb al-Ādāb al-kabīr can only be understood, if we take into account the meanings of concepts, as shaped in their historical context and reflecting the process of association and dissociation.