The normative role of logic for reasoning

This paper advocates for the normative role of logic in reasoning. I offer a response, anchored in an externalist perspective, to two fronts of attack against the normativity thesis, namely Harman’s sceptical challenge and the accusation of naturalistic fallacy. On the one hand, I rework dialogical bridge principles and show that such principles satisfy adequacy criteria to deal with Harman’s challenge. On the other hand, I argue that it is possible to derive normative consequences from logical facts. This is because argumentative interactions among agents involve the acceptance of constitutive rules that entail obligations. Hence, since logical rules can be seen as constitutive of the social practice of reasoning, they create prescriptions for reasoning. Bridge principles make those obligations and prohibitions explicit.