1

The reliability of non-financial ratings is strongly criticized (Tatomir 2023; Utz 2019; Widyawati 2021). Most financial players are aware of these limitations and have alternatives to avoid having to use them. Paradoxically, these same players are usually the first to endorse them. How can we explain these a priori counter-intuitive, even irrational behaviors? Various concepts can shed light on this: “management fashion” (Abrahamson 1996), “collective beliefs” (Orlean 2008), “cognitive biases” (Thaler 1980), “mimetic behaviors” (Esposito 2013), and so on. Our research aims to enrich this theoretical framework with a comprehensive perspective that avoids assuming that financial actors’ judgment is somehow flawed. To this end, we rework the concept of “ideology” on the basis of Boudon's work (1986), complemented by that of Piketty (2019). Our aim is to show that, once rigorously defined, this concept will make it possible to draw a clear distinction between the scientific and non-scientific aspects of the success of ESG ratings. Thus defined, ideology gives rise to “good reasons” to explain the apparent irrationality of financial actors’ choices.