The fiscal theory constitutes the key aspect of the Physiocratic program. From its onset it is one of the major themes of this school. In addition, Quesnay’s famous “Tableau économique”is, for his followers, the best way to justify their tax reform project. As we know, the objective of this program is to replace all the deductions by a single tax on the net product raised from the landlords, but an analysis of the Physiocrats’theses (as well as the ones of their allies) leads us to question the received idea of a strict doctrine: – The indirect taxes are always their main objects of criticism, but Physiocrats oscillate between the radical theoretical position of a single tax and a more pragmatic attitude towards taxation. – The taxation principle is always the touchstone of their reform project, but sometimes it is justified through the fictive deal made between the sovereign and his subjects, while other times it is referred to as a form of “co-ownership”of the sovereign over all the lands. – To make the analysis even more complex, it is important to point out that the controversies over taxation have always been a contentious topic for the sovereign power. To be able to navigate through this mined field, Physiocrats had to be extremely careful and even adopt a doublespeak. In this regard, it is useful to compare the texts of the leaders of the Physiocratic movement and the actual practice of the only minister that they consider to be their disciple: Turgot. If his position was in line with the Physiocratic viewpoint, he criticized the practical modalities by which the reforms could be implemented, a critique for which he could rely on his unquestionable qualities of administrator.