`titrebMontesquieu and the new political economy : inter-group inequality and political regimes transitions`/titrebThe importance of The Spirit of laws for the political and economic thought is well-known. The aim of the paper is to reconsider the famous statements on political stability through the recent developments of New Political Economy. More precisely, we show that, as in many models of NPE, economic inequality is considered by Montesquieu as one of the key-element of political transitions. By insisting on republican government, we provide a definition of the republican virtue as an inequality aversion that should be moderated in republican to avoid political instability.Classification JEL : B1, H3, K0`np pagenum="624"/b