Keith Frankish

This commentary does three things. First, it offers further support for the view that explicit reasoning evolved for public argumentation. Second, it suggests that promoting effective communication may not be the only, or even the main, function of public argumentation. Third, it argues that the data Mercier and Sperber (M&S) cite are compatible with the view that reasoning has subsequently been co-opted to play a role in individual cognition

Carruthers suggests that natural language, in the form of inner speech, may be the vehicle of conscious propositional thought, but he argues that its fundamental cognitive role is as the medium of cross-modular thinking, both conscious and nonconscious. I argue that there is no evidence for nonconscious cross-modular thinking and that the most plausible view is that cross-modular thinking, like conscious propositional thinking, occurs only in inner speech.