Abstract

Dual process theory proposes clusters of features that form two dichotomous groups in cognition. One standing internal issue is defining what the reference of these two dichotomous groups could be in the mind or brain. Does dual process theory speak of two systems, types, minds, modes, kinds or just metaphors? A particular common answer is that differences in clusters of features are evidence of different underlying systems, often called system 1 and system 2. However, the suggestion to abandon the ‘system’ terminology is now common in the literature, but the consequences of doing so need to be addressed. This work reviews and critically discusses previous suggestions.