know his person. If we do not know him, we shall yet take some one to be our invalid, but not a man of the lowest class, so that he may come to mind at once. And we shall place the defendant at the bedside, holding in his right hand a cup, and in his left hand tablets, and on the fourth finger a ram's testicles (Latin testiculi suggests testes or witnesses). In this way we can record the man who was poisoned, the inheritance, and the witnesses. In order to memorize likenesses based on words he provides an example of a verse and describes how images may be placed, each of which corresponds to words in the verse. He notes however that the technique will not work without combination with rote memorization of the verse, so that the images call to mind the previously memorized words. The architectural mnemonic was also related to the broader concept of learning and thinking. Aristotle considered the technique in relation to topica, or conceptual areas or issues. In his Topics he suggested For just as in a person with a trained memory, a memory of things themselves is immediately caused by the mere mention of their places, so these habits too will make a man readier in reasoning, because he has his premisses classified before his mind's eye, each under its number. Graphical mnemonic The architectural mnemonic is often characterized as the art of memory itself. However primary sources show that from very early in the development of the art, non-physical or abstract locations and/or spatial graphics were employed as memory 'places'. Perhaps the most famous example of such an abstract system of 'places' is the memory system of Metrodorus of Scepsis, who was said by Quintilian to have organized his memory using a system of backgrounds in which he "found three hundred and sixty places in the twelve signs of the zodiac through which the sun moves". Some researchers (L.A. Post and Yates) believe it likely that Metorodorus organized his memory using places based in some way upon the signs of the zodiac. In any case Quintilian makes it clear that non-alphabetic signs can be employed as memory images, and even goes on to mention how 'shorthand' signs (notae) can be used to signify things that would otherwise be impossible to capture in the form of a definite image (he gives "conjunctions"