Mnemonics (from Gr. ,uvavOat., remember; whence ,uvnµcev, mindful; rò j w /um/LK v, sc. Tixvn,ua, that which mechanically aids the memory), the general name applied to devices for aiding the memory. Such devices are also described as memoria technica. The principle is to enable the mind to reproduce a relatively unfamiliar idea, and specially a series of dissociated ideas, by connecting it, or them, in some artificial whole, the parts of which are mutually suggestive. A pupil is far more likely to remember the cities which claimed to be the birthplace of Homer when he remembers that their names can be made to form the hexameter line, "Smyrna, Chios, Colophon, Salamis, Rhodos, Argos, Athenae." Among the most famous examples of metrical mnemonics are the "gender rhymes" of the Latin grammars, the hexameter lines (especially that beginning "Barbara Celarent") invented by logicians (for a list see Baldwin's Dict. of Philos., vol. ii., s.v, " Mnemonic Verses"), the verse for remembering the number of days in the months ("Thirty days hath September, April, June and November"). Other devices are numerous. Thus the name and lights of the sides of a ship may be remembered because the three shorter words "port," "left," "red," go together, as compared with the longer, "starboard," "right," "green." Memory is commonly classified by psychologists according as it is exercised (a) mechanically, by attention and repetition; (b) judiciously, by careful selection and co-ordination; and (c) ingeniously, by means of artifices, i.e. mnemotechny, mnemonics. It must, however, be observed that no mnemonic is of any value which does not possess the qualities of (a) and (b). A mnemonic is essentially a device which uses attention and repetition, and careful selection is equally necessary. A more accurate description of mnemonics is "mediate" or "indirect" memory. In the technical sense the word "mnemonic" is confined to the systems of general application which have been elaborated by various writers.
Systems
Mnemonic devices were much cultivated by Greek sophists and philosophers, and are repeatedly referred to by Plato and Aristotle. In later times the invention was ascribed to the poet Simonides, 1 perhaps for no other reason than that the strength of his memory was famous. Cicero, who attaches 1 Pliny, H.N. vii. 24. Cicero, De or. ii. 86, mentions this belief without committing himself to it.
considerable importance to the art, but more to the principle of order as the best help to memory, speaks of Carneades (or perhaps Charmades) of Athens and Metrodorus of Scepsis as distinguished examples of the use of well-ordered images to aid the memory. The latter is said by Pliny to have carried the art so far "ut nihil non iisdem verbis redderet auditum." The Romans valued such helps as giving facility in public speaking. The method used is described by the author of Rhet. ad Heren., iii. 16-24; see also Quintilian (Inst. Or. xi. 2), whose account is, however, somewhat incomplete and obscure. In his time the art had almost ceased to be practised. The Greek and Roman system of mnemonics was founded on the use of mental places and signs or pictures, known as "topical" mnemonics. The most usual method was to choose a large house, of which the apartments, walls, windows, statues, furniture, &c., were severally associated with certain names, phrases, events or ideas, by means of symbolic pictures; and to recall these it was only necessary to search over the apartments of the house till the particular place was discovered where they had been deposited by the imagination. In accordance with this system, if it were desired to fix an historic date in the memory, it was localized in an imaginary town divided into a certain number of districts, each with ten houses, each house with ten rooms, and each room with a hundred quadrates or memory-places, partly on the floor, partly on the four walls, partly on the roof. Thus, if it were desired to fix in the memory the date of the invention of printing (1436), an imaginary book, or some other symbol of printing, would be placed in the thirty-sixth quadrate or memory-place of the fourth room of the first house of the historic district of the town. Except that the rules of mnemonics are referred to by Martianus Capella, nothing further is known regarding the practice of the art until the 13th century. Among the voluminous writings of Roger Bacon is a tractate De arte memorativa. Raimon Lull devoted special attention to mnemonics in connexion with his ars generalis. The first important modification of the method of the Romans was that invented by the German poet Konrad Celtes, who, in his Epitoma in utramque Ciceronis rhetoricam cum arte memorativa nova (1492), instead of places made use of the letters of the alphabet. About the end of the 15th century Petrus de Ravenna (b. 1448) awakened such astonishment in Italy by his mnemonic feats that he was believed by many to be a necromancer. His Phoenix artis memoriae (Venice, 1491, 4 vols.) went through as many as nine editions, the seventh appearing at Cologne in 1608. An impression equally great was produced about the end of the 16th century by Lambert Schenkel (Gazophylacium, 1610), who taught mnemonics in France, Italy, and Germany, and, although he was denounced as a sorcerer by the university of Louvain, published in 1593 his tractate De memoria at Douai with the sanction of that celebrated theological faculty. The most complete account of his system is given in two works by his pupil Martin Sommer, published at Venice in 1619. In 1618 John Willis (d. 1628?) published Mnemonica; sive ars reminiscendi (Eng. version by Leonard Sowersby, 1661; extracts in Feinaigle's New Art of Memory, 3rd ed., 1813), containing a clear statement of the principles of topical or local mnemonics. Giordano Bruno, in connexion with his exposition of the ars generalis of Lull, included a memoria technica in his treatise De umbris idearum. Other writers of this period are the Florentine Publicius (1482); Johann Romberch (1533); Hieronimo Morafiot, Ars memoriae (1602); B. Porta, Ars reminiscendi (1602).
In 1648 Stanislaus Mink von Wenussheim or Winckelmann made known what he called the "most fertile secret" in mnemonics - namely, the use of consonants for figures, so as to express numbers by words (vowels being added as required); and the philosopher Leibnitz adopted an alphabet very similar to that of Winckelmann in connexion with his scheme for a form of writing common to all languages. Winckelmann's method, which in fact is adopted with slight changes by the majority of subsequent "original" systems, was modified and supplemented in regard to many details by Richard Grey (1694-1771), who published a Memoria technica in 1730. The principal part of Grey's method (which may be compared with the Jewish system by which letters also stand for numerals, and therefore words for dates) is briefly this: "To remember anything in history, chronology, geography, &c., a word is formed, the beginning whereof, being the first syllable or syllables of the thing sought, does, by frequent repetition, of course draw after it the latter part, which is so contrived as to give the answer. Thus, in history, the Deluge happened in the year before Christ two thousand three hundred forty-eight; this is signified by the word Del-etok, Del standing for Deluge and etok for 2348." To assist in retaining the mnemonical words in the memory they were formed into memorial lines, which, however, being composed of strange words in difficult hexameter scansion, are by no means easy to memorize. The vowel or consonant, which Grey connected with a particular figure, was chosen arbitrarily; but in 1806 Gregor von Feinaigle, a German monk from Salem near Constance, began in Paris to expound a system of mnemonics, one feature (based on Winckelmann's system) of which was to represent the numerical figures by letters chosen on account of some similarity to the figure to be represented or some accidental connexion with it. This alphabet was supplemented by a complicated system of localities and signs. Feinaigle, who apparently published nothing himself, came to England in 1811, and in the following year one of his pupils published The New Art of Memory, which, beside giving Feinaigle's system, contains valuable historical material about previous systems. A simplified form of Feinaigle's method was published by Aime Paris (Principes et applications diverses de la mnemonique, 7th ed., Paris, 1834), and the use of symbolic pictures was revived in connexion with the latter by a Pole, Antoni Jaiwifisky, of whose system an account was published by the Polish general J. Bern, under the title Exposé general de la methode mnemonique polonaise, perfectionnee a Paris (Paris, 1839). Various other modifications of the systems of Feinaigle and Aime Paris were advocated by subsequent mnemonists, among them being the Phrenotypics of Major Beniowsky, a Polish refugee, the Phreno-Mnemotechny (1845) of Francois Fauvel Gouraud the Mnemotechnik of Karl Otto Reventlow (generally known as Karl Otto), a Dane, and the Mnemotechny of the American Pliny Miles.
The more complicated mnemonic systems have fallen almost into complete disuse; but methods founded chiefly on the so-called laws of association (see Association Of Ideas) have been taught with some success in Germany by, among others, Hermann Kothe, author of Lehrbuch der Mnemonik (2nd ed., Hamburg, 1852), and Katechismus der Gedeichtnisskunst (6th ed. by Montag, Leipzig, 1887); and Hugo Weber-Rumpe, author of Mnemonische Zahlworterbuch (Breslau, 1885) and Mnemonische Unterrichtsbriefe (1887-1888); in England by Dr Edward Pick, whose Memory and the Rational Means of Improving it (5th ed., 1873) and Lectures on Memory Culture (1899) obtained a wide circulation. Passing over the work of William Day (New Mnemonical Chart and Guide to the Art of Memory, 1845), Rev. T. Brayshaw (Metrical Mnemonics, a very rare work), Fairchild and W. Stokes, the next name of any importance is the Rev. J. H. Bacon, a pupil of Edward Pick. His book (A Complete Guide to the Improvement of the Memory, 3rd ed., rev. 1890) contains a good summary of the history of mnemonics and a very reasonable account of the principles; it gains in value by its comparative simplicity. More or less successful systems were issued by Lyon Williams (1866), T. Maclaren (1866), Thomas A. Sayer (1867), Rev. Alexander Mackay (1869), George Crowther (1870), F. Appleby (1880), John Sambrook, who made use of similarities in sounds (gun, i; Jew, 2), the French scientist Abbe Moigno, J. H. Noble, and Allan Dalzell. Considerable interest was roused both in London and in America by the controversy which raged round the system of "Alphonse Loisette," who taught his "art of never forgetting" successively in London and Washington. It claimed to be original in system, but was attacked in England by F. Appleby and in America by George S. Fellows, and is generally regarded as both unoriginal and inferior on the whole to preceding systems (for the litigation in America see e.g. Part II. of Middleton's Memory Systems, pp. 96 sqq.). An interesting work (Memoranda mnemonics) was published by James Copner in 1893, containing a system based partly on the use of letters for figures and words for dates, as well as a large number of rhymes for remembering facts in biblical, Roman, Greek and English history. He made use of Grey's system, but endeavoured as far as possible to invent, where necessary, words and terminations which in themselves had some special fitness in place of Grey's monstrosities. More complicated systems are the Keesing Memory System (Auckland, 1896), the Smith-Watson System of Memory and Mental Training (Washington), and the Pelman memory system.
BIBLIOGRAPHY. - A large number of the works referred to in the text contain historical material. Among histories of the subject, see C. F. von Aretin, Systesnatische Anleitung zur Theorie and Praxis der Mnemonik (Sulzberg, 1810); A. E. Middleton, Memory Systems, Old and New (espec. 3rd rev. ed., New York, 1888), with bibliography of works from 1325 to 1888 by G. S. Fellows and account of the Loisette litigation; F. W. Colegrove, Memory (1901), with bibliography, pp. 353-3 6 1. (J. M. M.)