This paper provides new perspectives on the French liberal economist Jacques Rueff (1896-1978), especially as regards his early writings on unemployment. We aim to show that Rueff distinguishes the root causes of permanent unemployment in England (1919-1931) based upon an interesting reading of non-Euclidean geometry. Controversially, this enables him to locate the cause of unemployment in the stickiness of the wage/price ratio. Hence, arguing that reality remains inaccessible in itself, Rueff focuses on a succession of variables (price, wage, unemployment), supplemented by his concepts of rational ego and the reasoning machine, in order to approach this reality.