Mnemonic devices are methods for memorizing. The ancient Greek poet Simonides of Ceos is the legendary discoverer of mnemonic devices. Pleased by Simonides's praise, the twin gods Castor and Pollux called him from a banquet just before the hall collapsed. The other guests were mangled beyond recognition, but Simonides remembered the places they had been sitting and so was able to identify the dead. Such was the discovery of the method of loci (or locations). It became so much a part of the study of rhetoric that the most venerable of the Roman orators used the method of loci for memorizing their speeches. Their procedure was as follows: First, a series of locations (loci), such as those in a public building, were memorized. Second, some object was thought of to represent each important part of the oration, such as a spear to represent the tenth topic...