placed in a room. The importance of the visual sense in the art of memory would seem to lead naturally to the importance of a spatial context, given that our sight and depth-perception naturally position images seen within space. Order The positioning of images in visual space leads naturally to an order, furthermore, an order to which we are naturally accustomed as biological organisms, deriving as it does from the sense perceptions we use to orient ourselves in the world. This fact perhaps sheds light on the relationship between the artificial and the natural memory, which were clearly distinguished in antiquity. It is possible for one with a well-trained memory to compose clearly in an organized fashion on several different subjects. Once one has the all-important starting-place of the ordering scheme and the contents firmly in their places within it, it is quite possible to move back and forth from one distinct composition to another without losing one's place or becoming confused. Again discussing Hugh of St. Victor's works on memory, Carruthers clearly notes the critical importance of order in memory: One must have a rigid, easily retained order, with a definite beginning. Into this order one places the components of what one wishes to memorize and recall. As a money-changer ("nummularium") separates and classifies his coins by type in his money bag ("sacculum," "marsupium"), so the contents of wisdom's storehouse ("thesaurus," "archa"), which is the memory, must be classified according to a definite, orderly scheme. Limited sets Many works discussing the art of memory emphasize the importance of brevitas and divisio, or the breaking up of a long series into more manageable sets. This is reflected in advice on forming images or groups of images which can be taken in at a single glance, as well as in discussions of memorizing lengthy passages, "A long text must always be broken up into short segments, numbered, then memorized a few pieces at a time." This is known in modern terminology as chunking. Association Association was considered to be of critical importance for the practice of the art. However, it was clearly recognized that associations in memory are idiosyncratic, hence, what works for one will not automatically work for all. For this reason, the associative values given for images in memory texts are usually intended as examples and are not intended to be "universally normative". Yates offers a passage from Aristotle