When questioning whether political deception can be ethically warranted, two competing intuitions jump to the fore. First, political deception is a fact of human life, used in the realpolitik of governance. Second, the ethical warrant of truth asserts itself as inexorably and indefatigably preferable to falsehood. Unfortunately, a cursory examination of the history of philosophy reveals a paucity of models to marry these basic intuitions. Some thinkers (e.g., Augustine, Aquinas, Grotius, Kant, Mill, and Rawls) privilege the truth by neglecting the (...) realpolitik, i.e., the truth is inviolate. Others (e.g., Machiavelli, Bentham, and the often infamous caché of 20th century dictators) focus upon the realpolitik to the exclusion of the primacy of the truth. A third group of critical thinkers (e.g., Arendt and Bok) examine the topic but offer no positive, systematic treatment of deception. Lacking are theories which simultaneously recognize that political untruth is often necessary, but that untruth is only justified when a) truth is politically impossible, b) the necessity of untruth is demonstrable, and c) the truth can be replaced with a minimally injurious untruth. Plato offers one such account in the Republic, arguing that deceit must be applied medicinally to the city. However, his account is problematic in detail. One of Plato’s inheritors, the 10th century thinker al-Fārābī, advanced Plato’s theoretical account, arguing that political governance requires restrained political deception. This deception, the expression of philosophical truths through the symbols of religion, meets the criteria mentioned above, being necessary, demonstrably necessary, and minimally injurious. But while al-Fārābī provides a valuable model for what justified political deception could look like, the lengths to which he must go in order to create a viable model for political deception reveals the untenability of the notion of justified political deception writ large. One must orchestrate an entire cosmos around the notion, notably a cosmos that does not match our own. One must adopt very specific conceptions of human nature, association, and happiness, as well as a particular metaphysics and epistemology. For, while al-Fārābī shows that political deception can be justifiable, he also reveals its unjustifiability outside an idealized setting. (shrink)