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Pythagoras of Samos 

~580 B.C. to ~500 B.C. 

Final Paper

Math G

Dr. Ian Walton

Compiled By: Nazih Malak

Date: 02-May-01

Pythagoras 

I first heardof Pythagoras back in middle school around 12 years ago in my school back homein Lebanon and his name went anonymous until last semester.Pythagorass namere-appeared when I took a Geometry class math B here at Mission College.So whois this man?

Pythagoras is considered tobe the first real mathematician. As an extremely important Greek philosopherand mathematician and founder of the Pythagorean School, but very fewinformation is known about him and his life. The Pythagorean view of the worldconsisted of a belief that numbers were the keys to the various qualities ofmankind and matter. In the Pythagorean view, everything was composed ofnumbers, the explanation for any objects existence could only be found innumbers. This was a completely novel concept, because at that time, numbersexisted for practical purposes only, as a device for solving problems incalendar construction, building and commerce. Pythagoreans were the first whosaw a number as an idea, important in itself. They also made a distinctionbetween logistic (art of computation) and arithmetic (number theory).

Pythagoras wassupposedly born about 569 B.C. on an island of Samos, Ionia, located in theAegean Sea (see map below), although others will only estimate his birth betweenthe years of 550 or 560 B.C.


 
 
 
 
 
 
 

Pythagorasbirthplace

At firstglance, there seems to be a great deal of biographical material on Pythagoras,dating from the first centuries of the Christian era; but when history isstudied more closely, the information is fairly vague. Unlike many later Greekmathematicians, there are no documented writings attributed to Pythagoras. Itis believed that this is due to a society which he led, half-religious andhalf-scientific, which followed a code of concealment and therefore caused himto remain somewhat of a mysterious figure in history. It has been stated thatthose facts that we do know about Pythagoras may be unreliable, because many ofthe accounts of this great scholar carry an almost unreliable character. Agreat deal of material is still, to this day, considered legend and or myth.Sometimes Pythagoras is represented as a man of science, and sometimes as apreacher of mystic doctrines. Although some claim this to be a contradiction inideology, most historians feel that the union of mathematical genius andmysticism was actually a common bond, valid and necessary for the times inwhich he lived. The detailed accounts of how Pythagoras invented the musicalscale, performed miracles and pronounced prophecies further enhance theromantic mystique that surrounds his name.

Pythagoras' father's namewas Mnesarchus and his mother's name was Pythais.Mnesarchus was a merchant fromTyre (modern Lebanon), who supposedly brought corn to Samos at a time of famineand was granted citizenship of Samos as a mark of gratitude.As a childPythagoras may have spent his early years in Samos but is known to havetraveled widely with his father. There are accounts of Mnesarchus returning toTyre with Pythagoras. It is then believed that in Tyre, Pythagoras was taughtby Chaldaeans and the scholars of Syria. It is also documented that he was welleducated, learning to play the lyre, learning poetry and reciting Homer.Although all accounts of his physical appearance are likely to ambiguous, therewas one common description that is consistent in all the accounts. Pythagorashad a "striking" birthmark on his thigh.

There areconflicting viewpoints on which of his teachers had the most effect andinfluence on Pythagoras while he was a young man. One of the most important wasPherekydes who was widely believed to be the ultimate teacher of Pythagoras.The other two main figures who were considered to be a major influence onPythagoras and, at some point, introduced him to mathematical ideas were Thalesand his pupil Anaximander. Thales is accredited with influencing Pythagoras'interest in mathematics and astronomy, going as far as to advise him to travelto Egypt to learn more of these subjects. He was however, an old man by thetime they had met and although he did contribute to Pythagoras' ultimatedevelopment, he was probably unable to do more than steer him in a rightdirection. However, Thales' pupil Anazximander gave lectures in Miletus, whichPythagoras attended. Anazximander's lectures on geometry and cosmology and avariety of his other ideas were certain to influence Pythagoras' own views. Onepopular theory states that Pythagoras became a disciple of Anaximander, hisastronomy becoming a natural development of Anaximander's. His geometry is alsosaid to have descended from the teachings in Miletus.

To bettervisualize Pythagoras place on a historical timeline, the following chart servesas a good illustration. It shows the period between 600 BC and 200 BC, whichallows us to see Pythagoras place in the sequence of other philosophers andmathematicians of the period. 

A fewyears after the Polycrates seized control of the city of Samos, Pythagoras wentto Egypt. There is some evidence that suggests that at first the men werefriends, and that Polycrates wrote a letter of introduction for Pythagoras, butthat later they grew apart in their thinking. Pythagoras visited many templesand took part in discussions with priests. Eventually, he was accepted into thepriesthood at Diospolis after completing the rites necessary for admission.Pythagoras founded a school or society that he later continued in Italy. It wasultimately considered a religious philosophical society for which he conceivedregulations that were secret and expected to be obeyed. The society hadprotracted periods of silence, (leading to the belief that this is the reasonso little is known about him), celibacy and various other forms ofself-discipline. Some historians claim to have evidence that Pythagoras wouldnot allow his disciples to eat beans. Although there are conflicting opinionsas to whether he indeed forbade his disciples to eat beans, it is a goodillustration of historical uncertainty, which surrounds this man. It is known,that black and white beans were used for voting. It is entirely possible thatPythagoras was urging his students to remain apolitical, rather than attemptingto control their dietary habits! The school was instructed by Pythagoras todevote itself to the cultivation of philosophy, mathematics, music andgymnastics, the aim of the organization being primarily ethical.

In 525 B.C.,Cambyses, the King of Persia, invaded Egypt. Polycrates abandoned his alliancewith Egypt and sent 40 ships to join the Persian fleet against the Egyptians.Cambyses won the Battle of Pelusium in the Nile Delta and captured Heliopolisand Memphis causing the Egyptian resistance to collapse. Pythagoras was takenprisoner and brought to Babylon. While prisoner, Pythagoras became anappropriate student in the sacred rites of the Magoi and learned their mysticalworship of the gods. He also reached what was considered the epitome ofperfection in arithmetic and music and the other mathematical sciences taughtby the Babylonians. In approximately 520 B.C., Pythagoras left Babylon andreturned to Samos.Historians were not able to find any documentation on how hewas able to obtain his freedom. Pythagoras made a journey to Crete shortlyafter his return to Samos to study the systems of laws there. He then returnedand founded a school, which was called the "Semicircle." Drawing onthe notion that all the philosophers before him had ended their days on foreignsoil, Pythagoras decided to make his home in Crotone, a town in Southern Italy.Once at home in Crotone, Pythagoras founded a philosophical and religiousschool. Pythagoras was the head of that society with an inner circle offollowers known as mathematikoi. They lived permanently with Pythagoras and theSociety, had no personal possessions, and were vegetarians. They obeyed strictrules:

1)   At its deepest level, reality is mathematical in nature.

2)   Philosophy can be used for spiritual purification.

3)   The soul can rise to union with the divine.

4)   Certain symbols have a mystical significance.

5)   All brothers of the order should observe strict loyalty andsecrecy. 

Women as wellas men were permitted to become members of the Society, many of whom went on tobecome famous philosophers. Those members in the outer circle lived in theirown homes, coming to the Society during the day. They were allowed to ownpossessions and did not have to be vegetarians. Because of this secrecy it isdifficult to differentiate between the work of Pythagoras and that of the restof the group. They were interested in the principles of mathematics, theconcept of number, or a triangle or other mathematical figures and the abstractidea of proof. They saw the universe as a scale and a number, applying it tomusic, mathematics and astronomy. It is thought that Pythagoras himselfdiscovered the numerical ratios that determine the concordant intervals of themusical scale. Pythagoras determined that ten was the very best number: itcontained in itself the first four integers - one, two, three and four(1+2+3+4) and these written in dot notation formed a perfect triangle. Usinghis beliefs, he developed the Pythagorean theorem. This theorem contends thatthe sum of the squares of the sides of a right triangle is equal to the squareof the hypotenuse, hypotenuse being the side of a right-angled triangleopposite the right angle.

Throughout all ofhis teachings, Pythagoras proclaimed himself a philosopher, rather than amathematician. The circumstances of his death are unclear but his legacy liveson. Pythagoras and the early Order initially treated numbers concretely, aspatterns with pebbles, but over time the Pythagoreans developed and refinedtheir concept of number into the same abstract entity, which still existstoday. Though it is difficult to separate fact from fancy in some of thesurviving references to the Pythagoreans, it is generally conceded that theybegan number theory, and were responsible for the introduction and developmentof number mysticism in Western Society. 

Accordingto Kline, a famous Pythagorean Philolaus (425 B.C.E.) wrote that were it notfor number and its nature, nothing that exists would be clear to anybody eitherin itself or in its relation to other things...You can observe the power ofnumber exercising itself ... in all acts and the thoughts of men, in allhandicrafts and music.

To thePythagoreans, each number possessed its own special attributes. See for examplethe table below. 

Number

Property of the number

 

 

1

monad(unity) generator of numbers, the number of reason

dyad(diversity, opinion) first true female number

triad(harmony = unity + diversity) first true male number

4

(justice, retribution) squaring of accounts

(marriage) = first female + first male

(creation) = first female + first male + 1 ?

10 

(Universe) tetractys

In addition to theirother "personalities" the first four numbers had a special


significance in that theirsum accounted for all the possible dimensions:  

Number

Geometric property

Geometric shape

1

generator of dimension 

line of dimension 1 

triangle of dimension 2

tetrahedron of dimension 3

Addingup all of these we get 1+2+3+4 = 10. Since these were the only numbers thatwere needed to demonstrate all known objects (geometrically), then the sum ofall these objects, that is the sum of these numbers, was believed to representthe known Universe. The properties of the tetractys still have persuasiveinfluence in mystic cults of today. Some argue that it was the Pythagoreanveneration of the tetractys, not so much the number of digits on hands or feet,which is responsible for our present use of the base ten. In addition to thetetractys, the Pythagoreans developed other concepts of "fourness" innature such as the material elements of earth, air, fire, and water.

The Pythagoreansare also often thought by various historians to have discovered amicable numbers.Two numbers are amicable if each is the sum of the proper divisors (that is allthe divisors except the number itself) of the other.

For example 220 and 284 areamicable since the sum of the proper divisors of 220 are 1 + 2 + 4 + 5 + 10 +11 + 20 + 22 + 44 + 55 + 110 = 284 and the sum of the proper divisors of 284are 1 + 2 + 4 + 71 + 142 = 220. Superstitious people believed that twotalismans bearing this pair of numbers would seal a perfect friendship betweenthe wearers. The pair also became significant in magic, sorcery, and astrology.

Other numbers thatwere assigned mystical powers by the Pythagoreans were the perfect, deficient,and abundant numbers.

A number is perfect if it is equal to thesum of its proper divisors, is deficient if its sum falls short of the number,and is abundant if the sum exceeds the number. 6 is a perfect number (1 + 2 +3), 8 is deficient (1 + 2 + 4), and 12 is abundant (1 + 2 + 3 + 4 + 6).

Fortunately, indeveloping their number mysticism, the Pythagoreans also valued proof. To thisend they searched for the essential properties and definitions of many numbers.The following is a brief description of their ideas about numbers:

Many superstitionsbecame associated with the odd and even numbers. For example the odds weregenerally regarded as masculine and divine, while the evens were consideredfeminine and thus earthly and human. An interesting fact is that due to theinfluence of Pythagoras, the Pythagoreans welcomed women into their Society,and that Pythagoras' wife, Theano, was considered an accomplished mathematicianin her time. Theano and her daughters are believed to have carried onPythagoras work after his death.

 

Figurate Number

Geometric shape

 

triangular numbers

 

square numbers

 

pentagonal numbers

 

oblong numbers

 

Needlessto say, the concept Pythagoras is best known for is the Pythagorean Theorem. Itis generally accepted that he was the first to give a general proof for therelationship, which states that: The square of the length of the hypotenuse ofa right triangle is equal to the sum of the squares of the legs, or in short:a2 + b2 = c.ThePythagorean theorem is one of the most famous in all of mathematics. There aremany different proofs of the theorem (even one supplied by President Garfield in1876!), and we know that the Babylonians knew about the Pythagorean theoremabout 1000 years before the time of Pythagoras. Nonetheless, a rigorous,general proof of the theorem requires the development of deductive geometry,and thus it is thought that Pythagoras probably supplied the first proof. Mostmath historians credit him with a proof by dissection, which relies on the useof two squares, one inscribed inside the other.


 

 

 

Let us put the Pythagoreantheorem to the test.In a right triangle ABC (C is the right angle), a = 12 cm,b = 7 cm.Find the length of the hypotenuse, c. 

1)      =         

2) =

3) 

 

 

Althoughit is difficult to separate Pythagoras personal discoveries from those of theSociety of his disciples, who tended to attribute their own discoveries to him,the fact remains that Pythagoras was responsible for a substantial amount ofrevolutionary ideas and concepts that helped channel the areas of Mathematics,Geometry and Music in the general direction being followed today. To givecredit where it is due, we must acknowledge, that although there areindications that some of the concepts attributed to Pythagoras were known toancient Babylonians prior to his time, the clear formulation of these conceptsand the cohesive force needed to integrate and synthesize theory from thoseconcepts must be attributed to Pythagoras and his followers.Considering thepervasive influence of Mathematics on nearly every aspect of modern life, it isdoubtless that Pythagorean ideas played a major part in shaping the face of ourmodern world!

Bibliography

Kline, Morris B., Mathematics- TheLoss of Certainty, N.Y.: Oxford University Press, 1980 

Heath, Sir Thomas L., Euclid - The ThirteenBooks of The Elements Second Edition Vol I, N.Y.: Dover Publications (orig.1908) 

T. Pappas, The Joy of Mathematics, Wide WorldPublishing/Tetra, 1989 

Internet:

http://www.mathgym.com.au/history/pythagoras/pyth.htm

http://www-groups.dcs.st-and.ac.uk/~history/Mathematicians/Pythagoras.html

http://www.utm.edu/research/iep/p/pythagor.htm 

http://history.hanover.edu/texts/presoc/pythagor.htm

http://www.math.sfu.ca/histmath/Europe/Euclid300BC/PYTHAGORAS.HTML

http://www.newadvent.org/cathen/12587b.htm 

http://forum.swarthmore.edu/~isaac/problems/pythagthm.html