The psychology of memory has been the site of major debates over the comparative status of experiments and qualitative methods. Despite efforts to combine these methods in various ways, research has for the most part developed along entirely distinct lines. In this paper, I argue that this apparent methodological division is structured around different orientations to 'bottom line' arguments over the possibility of establishing the veracity of recollections. Drawing on Stengers' 'cosmopolitical' approach to relations between practices, I explore parasitic and symbiotic relations between the approaches that bypass the difficulty of conjugating rival ontologies.