Art of memory

Perhaps the most important principle of the art is the dominance of the visual sense in combination with the orientation of 'seen' objects within space. This principle is reflected in the early Dialexis fragment on memory, and is found throughout later texts on the art. Mary Carruthers, in a review of Hugh of St. Victor's Didascalion, emphasizes the importance of the visual sense as follows:

Even what we hear must be attached to a visual image. To help recall something we have heard rather than seen, we should attach to their words the appearance, facial expression, and gestures of the person speaking as well as the appearance of the room. The speaker should therefore create strong visual images, through expression and gesture, which will fix the impression of his words. All the rhetorical textbooks contain detailed advice on declamatory gesture and expression; this underscores the insistence of Aristotle, Avicenna, and other philosophers, on the primacy and security for memory of the visual over all other sensory modes, auditory, tactile, and the rest.[22]

This passage emphasizes the association of the visual sense with spatial orientation. The image of the speaker is 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.

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.[23]

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.[24]

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."[25] This is known in modern terminology as chunking.

Congestorium artificiose memoriae, by Johann Romberch

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 that briefly outlines the principle of association. In it, he mentions the importance of a starting point to initiate a chain of recollection, and the way in which it serves as a stimulating cause.

For this reason some use places for the purposes of recollecting. The reason for this is that men pass rapidly from one step to the next; for instance from milk to white, from white to air, from air to damp; after which one recollects autumn, supposing that one is trying to recollect the season.[26]

The importance of affect or emotion in the art of memory is frequently discussed. The role of emotion in the art can be divided into two major groupings: the first is the role of emotion in the process of seating or fixing images in the memory, the second is the way in which the recollection of a memory image can evoke an emotional response.

One of the earliest sources discussing the art, the Ad Herennium emphasizes the importance of using emotionally striking imagery to ensure that the images will be retained in memory:

We ought, then, to set up images of a kind that can adhere longest in memory. And we shall do so if we establish similitudes as striking as possible; if we set up images that are not many or vague but active; if we assign to them exceptional beauty or singular ugliness; if we ornament some of them, as with crowns or purple cloaks, so that the similitude may be more distinct to us; or if we somehow disfigure them, as by introducing one stained with blood or soiled with mud and smeared with red paint, so that its form is more striking, or by assigning certain comic effects to our images, for that, too, will ensure our remembering them more readily.[27]

On the other hand, the image associated with an emotion will call up the emotion when recollected. Carruthers discusses this in the context of the way in which the trained medieval memory was thought to be intimately related with the development of prudence or moral judgement.

Since each phantasm is a combination not only of the neutral form of the perception, but of our response to it (intentio) concerning whether it is helpful or hurtful, the phantasm by its very nature evokes emotion. This is how the phantasm and the memory which stores it helps to cause or bring into being moral excellence and ethical judgement.[28]

In modern terminology, the concept that contains salient, bizarre, shocking, or simply unusual information will be more easily remembered. This can be referred to as the Von Restorff effect.

The well-known role of repetition in the common process of memorization of course plays a role in the more complex techniques of the art of memory. The earliest of the references to the art of memory, the Dialexis, mentioned above, makes this clear: "repeat again what you hear; for by often hearing and saying the same things, what you have learned comes complete into your memory."[29] Similar advice is a commonplace in later works on the art of memory.

The architectural mnemonic was a key group of techniques employed in the art of memory. It is based on the use of places (Latin loci), which were memorized by practitioners as the framework or ordering structure that would 'contain' the images or signs 'placed' within it to record experience or knowledge. To use this method one might walk through a building several times, viewing distinct places within it, in the same order each time. After the necessary repetitions of this process, one should be able to remember and visualize each of the places reliably and in order. If one wished to remember, for example, a speech, one could break up the content of the speech into images or signs used to memorize its parts, which would then be 'placed' in the locations previously memorized. The components of the speech could then be recalled in order by imagining that one is walking through the building again, visiting each of the loci in order, viewing the images there, and thereby recalling the elements of the speech in order. A reference to these techniques survives to this day in the common English phrases "in the first place", "in the second place", and so forth.[30] These techniques, or variants, are sometimes referred to as "the method of loci", which is discussed in a separate section below.

The primary source for the architectural mnemonic is the anonymous Rhetorica ad Herennium, a Latin work on rhetoric from the first century BCE. It is unlikely that the technique originated with the author of the Ad Herennium. The technique is also mentioned by Cicero and Quintilian. According to the account in the Ad Herennium (Book III) backgrounds or 'places' are like wax tablets, and the images that are 'placed' on or within them are like writing. Real physical locations were apparently commonly used as the basis of memory places, as the author of the Ad Herennium suggests

it will be more advantageous to obtain backgrounds in a deserted than in a populous region, because the crowding and passing to and fro of people confuse and weaken the impress of the images, while solitude keeps their outlines sharp.[31]

However, real physical locations were not the only source of places. The author goes on to suggest

if we are not content with our ready-made supply of backgrounds, we may in our imagination create a region for ourselves and obtain a most serviceable distribution of appropriate backgrounds.[32]

Places or backgrounds hence require, and reciprocally impose, order (often deriving from the spatial characteristics of the physical location memorized, in cases where an actual physical structure provided the basis for the 'places'). This order itself organizes the images, preventing confusion during recall. The anonymous author also advises that places should be well lit, with orderly intervals, and distinct from one another. He recommends a virtual 'viewing distance' sufficient to allow the viewer to encompass the space and the images it contains with a single glance.

Turning to images, the anonymous author asserts that they are of two kinds: those establishing a likeness based upon subject, and those establishing a likeness based upon a word. This was the basis for the subsequent distinction, commonly found in works on the art of memory, between 'memory for words' and 'memory for things'. He provides the following famous example of a likeness based upon subject:

Often we encompass the record of an entire matter by one notation, a single image. For example, the prosecutor has said that the defendant killed a man by poison, has charged that the motive for the crime was an inheritance, and declared that there are many witnesses and accessories to this act. If in order to facilitate our defense we wish to remember this first point, we shall in our first background form an image of the whole matter. We shall picture the man in question as lying ill in bed, if we 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.[33]

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.[34]

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.[35] 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" as an example).[36]

This makes it clear that though the architectural mnemonic with its buildings, niches and three-dimensional images was a major theme of the art as practiced in classical times, it often employed signs or notae and sometimes even non-physical imagined spaces. During the period of migration of barbarian tribes and the transformation of the Roman empire the architectural mnemonic fell into disuse. However the use of tables, charts and signs appears to have continued and developed independently. Mary Carruthers has made it clear that a trained memory occupied a central place in late antique and medieval pedagogy, and has documented some of the ways in which the development of medieval memorial arts was intimately intertwined with the emergence of the book as we understand it today. Examples of the development of the potential inherent in the graphical mnemonic include the lists and combinatory wheels of the Majorcan Ramon Llull. The Art of Signs (Latin Ars Notoria) is also very likely a development of the graphical mnemonic. Yates mentions Apollonius of Tyana and his reputation for memory, as well as the association between trained memory, astrology and divination.[37] She goes on to suggest

It may have been out of this atmosphere that there was formed a tradition which, going underground for centuries and suffering transformations in the process, appeared in the Middle Ages as the Ars Notoria, a magical art of memory attributed to Apollonius or sometimes to Solomon. The practitioner of the Ars Notoria gazed at figures or diagrams curiously marked and called 'notae' whilst reciting magical prayers. He hoped to gain in this way knowledge, or memory, of all the arts and sciences, a different 'nota' being provided for each discipline. The Ars Notoria is perhaps a descendant of the classical art of memory, or of that difficult branch of it which used the shorthand notae. It was regarded as a particularly black kind of magic and was severely condemned by Thomas Aquinas.[38]

Carruthers's studies of memory suggest that the images and pictures employed in the medieval arts of memory were not representational in the sense we today understand that term. Rather, images were understood to function "textually", as a type of 'writing', and not as something different from it in kind.[39]

If such an assessment is correct, it suggests that the use of text to recollect memories was, for medieval practitioners, merely a variant of techniques employing notae, images and other non-textual devices. Carruthers quotes Pope Gregory I, in support of the idea that 'reading' pictures was considered to be a variation of reading itself.

It is one thing to worship a picture, it is another by means of pictures to learn thoroughly the story that should be venerated. For what writing makes present to those reading, the same picturing makes present to the uneducated, to those perceiving visually, because in it the ignorant see what they ought to follow, in it they read who do not know letters. Wherefore, and especially for the common people, picturing is the equivalent of reading.[39]

Her work makes clear that for medieval readers the act of reading itself had an oral phase in which the text was read aloud or sub-vocalized (silent reading was a less common variant, and appears to have been the exception rather than the rule), then meditated upon and 'digested' hence making it one's own. She asserts that both 'textual' activities (picturing and reading) have as their goal the internalization of knowledge and experience in memory.

The use of manuscript illuminations to reinforce the memory of a particular textual passage, the use of visual alphabets such as those in which birds or tools represent letters, the use of illuminated capital letters at the openings of passages, and even the structure of the modern book (itself deriving from scholastic developments) with its index, table of contents and chapters reflect the fact that reading was a memorial practice, and the use of text was simply another technique in the arsenal of practitioners of the arts of memory.

Institutional:

Individual: