2Mutual misunderstandings are a prevalent problem of the imagery debate. For example, Kosslyn claims that the enactive theory would essentially be a form of the pictorial theory if it would be fleshed-out sufficiently (Kosslyn et al., 2006, p. 92) while Thomas (1999), in contrast, clearly states fundamental incompatibilities between the two theories. Another example are the diverging opinions on the concept of a functional space in which mental images are claimed to be represented in the pictorial theory. A discussion between Pylyshyn (2002) and Kosslyn, Thompson, and Ganis (2002) shows that the interpretations of such a functional space go so far apart, that Pylyshyn (2002, p. 218) even states that the assumption of a functional space is either incorrect (and a literal space is actually meant) or that it would follow that the pictorial theory does not differ from his descriptive theory. These examples underscore the current inability to fully understand, compare, or evaluate the contemporary theories as a result of their ambiguous description, i.e., their lack of formalization.