Human adults possess the extraordinary ability to produce mental imagery about a wide variety of non-occurrent events. We can, for example, simulate the perception of different places, different times, different possibilities, or others’ perspectives. Findings from cognitive psychology, neuropsychology, and cognitive neuroscience suggest that all of these capacities rely on the same neuro-cognitive mechanism: episodic simulation. This ability produces mental imagery by constructively recombining elements of past experiences to simulate event representations. However, if episodic simulation indeed produces mental imagery, it (...) remains unclear how the non-imagistic aspects of its outputs become cognitively determined. In this article, I argue that there are (at least) four such non-imagistic ‘dimensions’ of episodic simulation: specificity, temporal orientation, subjectivity, and factuality. Further, I propose an account of the mechanisms which might be responsible for determining where a given output of episodic simulation falls within this dimensional space. According to this view, episodic simulation relies on propositional ‘scope-operators’ either deployed as inputs to the simulation process itself or produced by post-hoc monitoring processes operating over its outputs. This view has consequences for how we should view the operation, development, and evolution of episodic simulation. (shrink)