This article first locates Jacques Rancière’s account of politics in the context of French thinking in the second half of the 20th century. It then summarizes how Rancière defines politics in terms of an originary equality that supports all orders of command and obedience. For Rancière, also, the world as a ‘whole’ does not add up. It is characterized by ‘paradoxical magnitude’. Paradoxical magnitude means that every regime of politics will nonetheless also be a miscount, a ‘wrong’ that will in particular fail to satisfy the originary equality that is supposed by all ‘partitions of the sensible’. Since there is no metric by reference to which the ‘whole’ of the world can be made to add up, politics cannot be an epistemological question. For Rancière it is a matter of the polemical practices by which equality is verified through emancipation. The complex ‘taking place’ of emancipation is the theme of teaching what we do not know that preoccupies Rancière’s The Ignorant Schoolmaster. Here, the article argues, emancipation also finds a distinctly messianic expression. The aporetic difficulty of teaching what we do not know as an emancipatory practice is explored by reading The Ignorant Schoolmaster with and against Stanley Rosen’s reading of Plato’s Statesman, which poses the same problem but resolves it differently. The article concludes by asking what is at stake in this messianic expression of emancipation.