How to distinguish public and non-public reasons?

Jaffro, L. (2020). Comment distinguer raisons publiques et raisons non publiques? The Tocqueville Review., 41(1), 41-53. https://doi.org/10.3138/ttr.41.1.41

The paper discusses the distinction between two kinds of reasons, public and non-public, which plays a major role in the way John Rawls sought to respond to communitarian criticisms, and which Catherine Audard revisits to advocate a political philosophy that confronts what she calls cultural fragmentation. Should public reasons be conceived as being of an argumentative nature, quite different from that of non-public reasons? Or should we consider that the difference is primarily between their objects, and contrast the adoption of a policy or line of conduct with beliefs and valuations that may also respond to reasons?