# Nicomachus

Nicomachus, or Nicomachus of Gerasa, (Greek: Νικόμαχος; c. 60 – c. 120 CE) was an important ancient Greek mathematician best known for Introduction to Arithmetic and Manual of Harmonics. He was born in Gerasa, in the Roman province of Syria (now Jerash, Jordan). Although a Neopythagorean who wrote about the mystical properties of numbers, Nicomachus was strongly influenced by Aristotle.

## Quotes
### Nicomachus of Gerasa: Introduction to Arithmetic (1926)

    Translated from Arithmetike eisagoge (ca. 100 AD) by Martin Luther D'Ooge, with studies in Greek arithmetic by Frank Egleston Robbins and Louis Charles Karpinski, source.
Book I, Chapter I
* The ancients, who under the leadership of Pythagoras first made science systematic, defined philosophy as the love of wisdom... [Οἱ παλαιοὶ καὶ πρώτοι μεθοδεύσαντες ἐπιστήμην κατάρξαντος Πυθαγόρου ὡρίζοντο φιλοσοφίαν εἶναι φιλίαν σοφίας...] This 'wisdom' he defined as the knowledge, or science, of the truth in real things, conceiving 'science' to be a steadfast and firm apprehension of the underlying substance. and 'real things' to be those which continue uniformly and the same in the universe and never depart even briefly from their existence; these real things would be things immaterial...
** Commentary (p.92): Nichomacus is an idealist. He states his position in a way that recalls Plato's distinction between "that which ever exists, having no becoming" and "that which is ever becoming, never existent,"... On the one hand there are "the real things... which exist forever changeless and in the same way in the cosmos, never departing from their existence even for a brief moment," and on the other "the original eternal matter and substance" which was entirely "subject to deviation and change."
* Bodily, material things are... continuously involved in continuous flow and change—in imitation of the nature and peculiar quality of that eternal matter and substance which has been from the beginning... The bodiless things, however, of which we conceive in connection with or together with matter, such as qualities, quantities, configurations, largeness, smallness, equality, relations, actualities, dispositions, places, times, all those things... whereby the qualities in each body are comprehended—all these are of themselves immovable and unchangeable, but accidentally they share in and partake of the affections of the body to which they belong. Now it is with such things that 'wisdom' is particularly concerned, but accidentally also with... bodies.
Book I, Chapter II
* To quote the words of Timaeus, in Plato, "What is that which always is, and has no birth, and what is that which is always becoming but never is? The one is apprehended by the mental processes, with reasoning, and is ever the same; the other can be guessed at by opinion in company with unreasoning sense, a thing which becomes and passes away, but never really is." Therefore, if we crave for the goal which is worthy and fitting for man, namely happiness of life—and this is accomplished by philosophy alone and nothing else, and philosophy means... for us desire for wisdom, and wisdom the science of the truth of things... it is reasonable and most necessary to distinguish and systematize the accidental qualities of things.
* Things... are some of them continuous...which are properly and peculiarly called 'magnitudes'; others are discontinuous, in a side-by-side arrangement, and, as it were, in heaps, which are called 'multitudes,' a flock, for instance, a people, a heap, a chorus, and the like. Wisdom, then, must be considered to be the knowledge of these two forms. Since, however, all multitude and magnitude are by their own nature of necessity infinite—for multitude starts from a definite root and never ceases increasing; and magnitude, when division beginning with a limited whole is carried on, cannot bring the dividing process to an end... and since sciences are always sciences of limited things, and never of infinites, it is accordingly evident that a science dealing with magnitude... or with multitude... could never be formulated.... A science, however, would arise to deal with something separated from each of them, with quantity, set off from multitude, and size, set off from magnitude.
Book I, Chapter III
* Since of quantity, one kind is viewed by itself, having no relation to anything else, as 'even,' 'odd,' 'perfect,' and the like, and the other is relative to something else, and is conceived of together with its relationship to another thing, like' double,' , greater,' 'smaller,' 'half,' 'one and one-half times,' 'one and one-third times,' and so forth, it is clear that two scientific methods will lay hold of and deal with the whole investigation of quantity: arithmetic, [with] absolute quantity; and music, [with] relative quantity.
* Two other sciences in the same way will accurately treat of 'size': geometry, the part that abides and is at rest, [and] astronomy, that which moves and revolves.
* Without the aid of these, then, it is not possible to deal accurately with the forms of being nor to discover the truth in things, knowledge of which is wisdom, and evidently not even to philosophize properly, for "just as painting contributes to the menial arts toward correctness of theory, so in truth lines, numbers, harmonic intervals, and the revolutions of circles bear aid to the learning of the doctrines of wisdom," says the Pythagorean Androcydes. Likewise Archytas of Tarentum, at the beginning of... On Harmony, says... in about these words: "It seems to me that they do well to study mathematics, and it is not at all strange that they have correct knowledge about each thing, what it is. For if they knew rightly the nature of the whole, they were also likely to see well what is the nature of the parts. About geometry, indeed, and arithmetic and astronomy, they have handed down to us a clear understanding, and not least also about music. For these seem to be sister sciences; for they deal with sister subjects, the first two forms of being."
* Plato, too, at the end of the thirteenth book of the Laws, to which some give the title The Philosopher... adds: "Every diagram, system of numbers, every scheme of harmony, and every law of the movement of the stars, ought to appear one to him who studies rightly; and what we say will properly appear if one studies all things looking to one principle, for there will be seen to be one bond for all these things, and if anyone attempts philosophy in any other way he must call on Fortune to assist him. For there is never a path without these... The one who has attained all these things in the way I describe, him I for my part call wisest, and this I maintain through thick and thin." For it is clear that these studies are like ladders and bridges that carry our minds from things apprehended by sense and opinion to those comprehended by the mind and understanding, and from those material, physical things, our foster-brethren known to us from childhood, to the things with which we are unacquainted, foreign to our senses, but in their immateriality and eternity more akin to our souls, and above all to the reason which is in our souls.
** Footnote: The Epinomis, from which Nicomachus here quotes 991 D ff., is now recognized as not genuinely Platonic. Nicomachus doubtless cited the passage from memory, for he does not give it exactly...
* In Plato's Republic, when the interlocutor of Socrates appears to bring certain plausible reasons to bear upon the mathematical sciences, to show that they are useful to human life, arithmetic for reckoning, distributions, contributions, exchanges, and partnerships, geometry for sieges, the founding of cities and sanctuaries, and the partition of land, music for festivals, entertainment, and the worship of the gods, and the doctrine of the spheres, or astronomy, for farming, navigation and other undertakings, revealing beforehand the proper procedure and suitable season, Socrates, reproaching him says: "You amuse me, because you seem to fear that these are useless studies that I recommend; but that is very difficult, nay, impossible. For the eye of the soul, blinded and buried by other pursuits, is rekindled and aroused again by these and these alone, and it is better that this be saved than thousands of bodily eyes, for by it alone is the truth of the universe beheld."
Book I, Chapter IV
* If geometry exists, arithmetic must also needs be implied... But on the contrary 3, 4, and the rest might be 5 without the figures existing to which they give names. Hence arithmetic abolishes geometry along with itself, but is not abolished by it, and while it is implied by geometry, it does not itself imply geometry.
Book I, Chapter V
* And once more is this true in the case of music; not only because the absolute is prior to the relative, as 'great' to 'greater' and 'rich' to 'richer' and 'man' to 'father,' but also because the musical harmonies, diatessaron, diapente, and diapason, are named for numbers; similarly all of their harmonic ratios are arithmetical ones, for the diatessaron [perfect fourth] is the ratio of 4 : 3, the diapente [perfect fifth] that of 3 : 2, and the diapason [perfect octave] the double ratio [2 : 1]; and the most perfect, the di-diapason [fifteenth], is the quadruple ratio [4 : 1].
* More evidently still astronomy attains through arithmetic the investigations that pertain to it, not alone because it is later than geometry in origin—for motion naturally comes after rest—nor because the motions of the stars have a perfectly melodious harmony, but also because risings, settings, progressions, retrogressions, increases, and all sorts of phases are governed by numerical cycles and quantities. So then we have rightly undertaken first the systematic treatment of this, as the science naturally prior, more honorable, and more venerable, and, as it were, mother and nurse of the rest; and here we will take our start for the sake of clearness.
Book I, Chapter VI
* All that has by nature, with systematic method, been arranged in the universe, seems both in part and as a whole to have been determined and ordered in accordance with number, by the forethought and the mind of him that created all things; for the pattern was fixed, like a preliminary sketch, by the domination of number preëxistent in the mind of the world-creating God, number conceptual only and immaterial in every way, but at the same time the true and the eternal essence, so that with reference to it, as to an artistic plan, should be created all these things: time, motion, the heavens, the stars, all sorts of revolutions.
* Scientific number, being set over such things as these, should be harmoniously constituted, in accordance with itself; not by any other but by itself.
* Everything that is harmoniously constituted is knit together out of opposites...
Book I, Chapter VII
* Number is limited multitude or a combination of units or a flow of quantity made up of units; and the first division of number is even and odd.
* The even is that which can be divided into two equal parts without a unit intervening in the middle; and the odd is that which cannot...
Book I, Chapter VIII
* Every number is at once half the sum of the two on either side of itself...
Book II, Chapter XXV
* Some... agreeing with Philolaus, believe that the proportion is called harmonic because it attends upon all geometric harmony, and they say that 'geometric harmony' is the cube because it is harmonized in all three dimensions, being the product of a number thrice multiplied together. For in every cube this proportion is mirrored; there are in every cube 12 sides, 8 angles and 6 faces; hence 8, the [harmonic] mean between 6 and 12, is according to harmonic proportion...
** Note: this harmonic proportion may be expressed as ${\frac {12}{6}}={\frac {12-8}{8-6}}$ or inversely.

## Quotes about Nicomachus

* A Jew, Nicomachus, of Gerasa, published an Arithmetic, which, or rather a Latin translation of it) remained for a thousand years a standard authority on the subject. Geometrical demonstrations are here abandoned, and the work is a mere classification of the results then known, with numerical illustrations: the evidence of the truth of the propositions enunciated, for I cannot call them proofs, being in general an induction from numerical instances. The object of the book is the study of the properties of numbers, and particularly of their ratios. Nicomachus commences with the usual distinctions between even, odd, prime, and perfect numbers; he next discusses fractions in a somewhat clumsy manner; he then turns to polygonal and to solid numbers; and finally treats of ratio, proportion, and progressions. Arithmetic of this kind is usually termed Boethian, and the work of Boethius on it was a recognised text-book in the middle ages.
** W. W. Rouse Ball, A Short Account of the History of Mathematics (1912)
* The sixth century [BC] was the time, and Greece the place, for human beings to reject once and for all the pernicious number mysticism of the East. Instead, Pythagoras and his followers eagerly accepted it as the celestial revelation of a higher mathematical harmony. Adding vast masses of sheer numerological nonsense of their own to an already enormous bulk, they transmitted this ancient superstition to the golden age of Greek thought, which passed it on to the first century A.D. to the decadent arithmologist Nicomachus. He, enriching his already opulent legacy with a wealth of original rubbish, left it to be sifted by the Roman Boethius, the dim mathematical light of the Middle Ages, thereby darkening the mind of Christian Europe with the venerated nonsense, and encouraging the gemaria of the Talmudists to flourish like a weed.
** Eric Temple Bell, The Development of Mathematics (1940)
* "Arithmetic Introduction" is the most complete exposition extant of Pythagorean arithmetic. It deals in great part with the same subjects as the arithmetical books of Euclid's "Elements," but where Euclid represents numbers by straight lines, Nicomachus uses arithmetical notation with ordinary language when undetermined numbers are expressed. His treatment of polygonal numbers and pyramidal numbers was of influence on medieval arithmetic, especially through Boetius.
** Dirk Jan Struik, A Concise History of Mathematics (1948) Ch. 3 Greece
* Boetius wrote mathematical texts which were considered authoritative in the Western world for more than a thousand years. ...His "institutio arithmetica," a superficial translation of Nicomachus, did provide some Pythagorean number theory which was absorbed in medieval instruction as part of the ancient trivium and quadrivium: arithmetic, geometry, astronomy, and music.
** Dirk Jan Struik, A Concise History of Mathematics (1948) Ch. 5 The Beginning of Western Europe
* Neo-Pythagoreans, like Nicomachus of Gerasa... and Iamblichus... revel in... number mysticism. ...The purpose of the layman's Introduction to Arithmetic... is to explain in a manner intelligible to every one, the wonderful and divine properties of numbers. In a very entertaining way he tells about triangular numbers... square, rectangular and polygonal numbers... gnomic numbers and spatial numbers, about ratios and the distinction between multiple and epimoric.
** Bartel Leendert van der Waerden, Science Awakening (1954)

### The Arithmetical Philosophy of Nicomachus of Gersa (1916)

    George Johnson, source
* His native place was Gerasa probably the modern Jerash about 56 miles northeast of Jerusalem. Two treatises bear the name of Nicomachus, the Introductionis arithmeticæ libri duo and the Enchiridion harmonikon. ...A third treatise called Theologoumena arithmetica is anonymous but is probably the work of Nicomachus.
* In mathematical studies he is among the first to attempt a systematic treatment of Arithmetic distinct from Algebra.
* Nicomachus is preparing for the answer, mathematical knowledge, and so he says, the knowledge which distinguishes accurately "the accidents of the Existents." Accident may refer either to a contingent or to a necessary attribute... Here it is the latter. To distinguish such accidents seems at first glance an incredibly difficult task. But Nicomachus, like his descendants, simplifies it by reducing the accidents to two: Magnitude and Multitude.
* Nicomachus... mentions the customary Pythagorean divisions of quantum and the science that deals with each. Quantum is either discrete or continuous. Discrete quantum in itself considered, is the subject of Arithmetic; if in relation, the subject of Music. Continuous quantum, if immovable, is the subject of Geometry; if movable, of Spheric (Astronomy). These four sciences formed the quadrivium of the Pythagoreans. With the trivium (which Nicomachus does not mention) of Grammar, Logic, and Rhetoric, they composed the seven liberal arts taught in the schools of the Roman Empire.
* Nicomachus gives three definitions of number. The first, "determinate multitude," is by genus and difference, and is ascribed by Iamblichus to Eudoxus. The second, "a group (i.e., organized complex) of units," [Iamblichus] ascribes to Thales and the Egyptians. The third stream of quantity composed of units Philoponus explains as another attempt to distinguish the particular kind of quantum treated in Arithmetic. The Unit was conceived either mystically as an Idea whose "essence" passes in some way into concrete individuals and even into the Ideas to organize them, or spatially and temporally as the boundary of individuals. The former conception gave rise to fantastic speculations on the cosmic meaning of number, examples of which Nicomachus has... given us; the latter gave rise to the figurate numbers...

### Nicomachus of Gerasa: Introduction to Arithmetic (1926)

    Translated from Arithmetike eisagoge (ca. 100 AD) by Martin Luther D'Ooge, with studies in Greek arithmetic by Frank Egleston Robbins and Louis Charles Karpinski, source. The Preface reads "Professor Martin Luther D'Ooge died suddenly... His translation... was complete, but the supporting studies had not been commenced. ...Mr. Karpinsky contributed Chapters I, III, IV and the greater part of Chapter X of Part I, together with the first section of Part III, Extensions of a Theorem of Nicomachus; Mr. Robbins made the final revision of Mr. D'Ooge's translation and prepared the rest of the volume.
* The philosophical arithmetic of the Greeks, αριθμητική, of which the arithmetic of Nicomachus is a specimen, corresponds in a measure to our number theory; the subject was designed for mature students as a preparation for the study of philosophy, and was not at all intended for children. Arithmetica is... the study of that which is implied in number.
** Part I, Chapter I. The Sources of Greek Mathematics.
* The Introduction to Arithmetic of Nicomachus is but a restatement of facts which were common property... long before him, and that, except for the few unimportant propositions the discovery of which our author... claims for himself, the book is largely unoriginal. This naturally leads to the inference that the Introduction must be closely connected with other mathematical treatises, which served as the fountains... Because so little remains of this literature, [our inference] is difficult to demonstrate...
** Part I, Chapter II. The Development of the Greek Arithmetic before Nicomachus.
* Iamblichus, when he refers to the Introduction as the... Art of Arithmetic, exactly describes it... The Introduction belongs... among the artes or... concise, practical descriptions and systematic expositions of the principles of various arts and sciences, a type of treatise exceedingly common in ancient times, and one which... made scant claim to originality. Designed for the use of students... they may best be compared to the modern school and college text-book. ...we must consider that the Introduction to Arithmetic differs from the great original treatises of Diophantus and Heron. Because in clearness, conciseness, compendiousness, orderly arrangement and adaptability for scholastic use, it satisfied the demands of seekers after education or general information, it remained the standard work of its class for many centuries.
** Part I, Chapter II.
* Nicomachus planned his Introduction so as to explain the mathematical principles involved in the difficult Platonic passages concerning the world-soul in the Timaeus and the marriage-number in the Republic.
** Part I, Chapter II.
* In geometry we begin with the point, which is indimensional. This is the beginning of the first dimensional form, the line, and by movement the point generates the line. Now Nicomachus had a similar idea of the nature of multitude and number; they form a series, as it were a moving stream, which proceeds out of unity, the monad. Just as the point is not part of the line (for it is indimensional, and the line is defined as that which has one dimension), but is potentially a line, so the monad is not a part of multitude nor of number, though it is the beginning of both, and potentially both. The monad is unity, absence of multitude, potentiality; out of it the dyad first separates itself and 'goes forward' and then in succession follow the other numbers.
** Part I, Chapter VI. The Philosophy of Nicomachus.

## External links

* Nicomachus of Gerusa: Introduction to Arithmetic (1926). Tr. Martin Luther D'Ooge with studies in Greek arithmetic by Frank Egleston Robbins and Louis Charles Karpinski.
* "Nicomachus", at the MacTutor History of Mathematics archive