  First, note that proponents of the Way of Ideas commit themselves not only to the existence of ideas but to pressing ideas into a number of functional roles in the mental lives of human beings. But, according to Reid, the underlying rationale for these commitments is typically not even stated by proponents of the Way of Ideas; it is most often taken for granted, or supported with demonstrably weak arguments. As a result, the rationale for commitments to an ontology of ideas and to their functional roles in the mind does not confer upon that commitment much epistemic justification. In the context of a passage in which Reid imagines a dialogue between “the vulgar” or the common person on the one hand and “the philosopher” on the other, Reid develops this reasoning as follows: