Justifications for the Principle of Public Reason

The principle of public reason is invoked as a strategy to evaluate and guide political decisions in the face of disagreement. However, employing the strategy itself requires justification. This thesis centres on the debates concerning the justification for employing the principle of public reason. I argue for two main claims. First, there is an under-examined and problematic aim towards finding one justification for employing the principle of public reason, for all contexts and cases. This is the goal towards justificatory monism. Examining two sets of dialogues between public reason philosophers, I discuss how this aim accounts for the justificatory burdens these philosophers impose on themselves – as revealed by the criticisms they anticipate, and the objections they marshal against their rivals. Second, I argue for justificatory pluralism for employing the principle of public reason. If we want individuals to employ the principle, we must provide them with as many justifications for doing so as are available. This increases the likelihood that individuals with plural views will regard employing the principle as warranted, and as all-things-considered justified. In making the first claim, I discover six considerations that are relevant to the justification for employing the principle of public reason. While they are invoked by public reason philosophers in their discussions, their relevance has not been thoroughly considered. I organise these considerations, and argue that they not only motivate a re-framing of the existing discussions, but also justificatory pluralism. The second claim is established by scrutinising the deliberations of legislators and citizens. This reveals two problems – of pluralism and self-interest – which are better addressed by justificatory pluralism. I conclude by defending justificatory pluralism against several objections