 It is not clear whether introducing the term ‘mental imagery’ by example is particularly helpful, for at least two reasons. First, there are well-demonstrated interpersonal variations in mental imagery (see Section 1.2), so much so that some people report no experience whatsoever when closing their eyes and visualizing an apple. Second, it is unclear how such an example like visualizing an apple could be generalized in a way that would give us a coherent concept. It does not seem like mental imagery is an ordinary language term – it was introduced at the end of the 19th century (see Section 1.1 below) as a technical term in psychology and no languages other than English has a term that would mean mental imagery (as distinct from ‘imagination’ or ‘mental picture’). But if ‘mental imagery’ is indeed a technical term, then it is supposed to be used in a way that maximizes theoretical usefulness. In this case, theoretical usefulness means that we should use ‘mental imagery’ in a way that would help us to explain how the mind works.