"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."