CHAPTER XII. MATHEMATICAL MEMORIES: NEWTON'S BINOMIAL THEOREM

The spider's web is a glorious mathematical problem. I should enjoy

working it out in all its details, were I not afraid of wearying the

reader's attention. Perhaps I have even gone too far in the little that

I have said, in which case I owe him some compensation: 'Would you

like me,' I will ask him, 'would you like me to tell you how I acquired

sufficient algebra to master the logarithmic systems and how I became

a surveyor of Spiders' webs? Would you? It will give us a rest from

natural history.'

I seem to catch a sign of acquiescence. The story of my village school,

visited by the chicks and the porkers, has been received with some

indulgence; why should not my harsh school of solitude possess its

interest as well? Let us try to describe it. And who knows? Perhaps,

in doing so, I shall revive the courage of some other poor derelict

hungering after knowledge.

I was denied the privilege of learning with a master. I should be wrong

to complain. Solitary study has its advantages: it does not cast you in

the official mould; it leaves you all your originality. Wild fruit, when

it ripens, has a different taste from hothouse produce: it leaves on

a discriminating palate a bittersweet flavor whose virtue is all the

greater for the contrast. Yes, if it were in my power, I would start

afresh, face to face with my only counselor, the book itself, not always

a very lucid one; I would gladly resume my lonely watches, my struggles

with the darkness whence, at last, a glimmer appears as I continue to

explore it; I should retraverse the irksome stages of yore, stimulated

by the one desire that has never failed me, the desire of learning and

of afterwards bestowing my mite of knowledge on others.

When I left the normal school, my stock of mathematics was of the

scantiest. How to extract a square root, how to calculate and prove the

surface of a sphere: these represented to me the culminating points of

the subject. Those terrible logarithms, when I happened to open a

table of them, made my head swim, with their columns of figures; actual

fright, not unmixed with respect, overwhelmed me on the very threshold

of that arithmetical cave. Of algebra I had no knowledge whatever. I had

heard the name; and the syllables represented to my poor brain the whole

whirling legion of the abstruse.

Besides, I felt no inclination to decipher the alarming hieroglyphics.

They made one of those indigestible dishes which we confidently extol

without touching them. I greatly preferred a fine line of Virgil, whom I

was now beginning to understand; and I should have been surprised

indeed had any one told me that, for long years to come, I should be an

enthusiastic student of the formidable science. Good fortune procured me

my first lesson in algebra, a lesson given and not received, of course.

A young man of about my own age came to me and asked me to teach him

algebra. He was preparing for his examination as a civil engineer; and

he came to me because, ingenuous youth that he was, he took me for

a well of learning. The guileless applicant was very far out in his

reckoning.

His request gave me a shock of surprise, which was forthwith repressed

on reflection: 'I give algebra lessons?' said I to myself. 'It would be

madness: I don't know anything about the subject!'

And I left it at that for a moment or two, thinking hard, drawn now

this way, now that with indecision: 'Shall I accept? Shall I refuse?'

continued the inner voice.

Pooh, let's accept! An heroic method of learning to swim is to

leap boldly into the sea. Let us hurl ourselves head first into the

algebraical gulf; and perhaps the imminent danger of drowning will call

forth efforts capable of bringing me to land. I know nothing of what

he wants. It makes no difference: let's go ahead and plunge into the

mystery. I shall learn by teaching.

It was a fine courage that drove me full tilt into a province which I

had not yet thought of entering. My twenty-year-old confidence was an

incomparable lever.

'Very well,' I replied. 'Come the day after tomorrow, at five, and we'll

begin.'

This twenty-four hours' delay concealed a plan. It secured me the

respite of a day, the blessed Thursday, which would give me time to

collect my forces.

Thursday comes. The sky is gray and cold. In this horrid weather, a

grate well filled with coke has its charms. Let's warm ourselves and

think.

Well, my boy, you've landed yourself in a nice predicament! How will

you manage tomorrow? With a book, plodding all through the night, if

necessary, you might scrape up something resembling a lesson, just

enough to fill the dread hour more or less. Then you could see about the

next: sufficient for the day is the evil thereof. But you haven't the

book. And it's no use running out to the bookshop. Algebraical treatises

are not current wares. You'll have to send for one, which will take

a fortnight at least. And I've promised for tomorrow, for tomorrow

certain! Another argument and one that admits of no reply: funds are

low; my last pecuniary resources lie in the corner of a drawer. I count

the money: it amounts to twelve sous, which is not enough.

Must I cry off? Rather not! One resource suggests itself: a highly

improper one, I admit, not far removed indeed from larceny. O quiet

paths of algebra, you are my excuse for this venial sin! Let me confess

the temporary embezzlement.

Life at my college is more or less cloistered. In return for a modest

payment, most of us masters are lodged in the building; and we take our

meals at the principal's table. The science master, who is the big gun

of the staff and lives in the town, has nevertheless, like ourselves,

his own two cells, in addition to a balcony, or leads, where the

chemical preparations give forth their suffocating gases in the open

air. For this reason, he finds it more convenient to hold his class here

during the greater part of the year. The boys come to these rooms in

winter, in front of a grate stuffed full of coke, like mine, and there

find a blackboard, a pneumatic trough, a mantelpiece covered with glass

receivers, panoplies of bent tubes on the walls, and, lastly, a

certain cupboard in which I remember seeing a row of books, the oracles

consulted by the master in the course of his lessons.

'Among those books,' said I to myself, 'there is sure to be one on

algebra. To ask the owner for the loan of it does not appeal to me.

My amiable colleague would receive me superciliously and laugh at my

ambitious aims. I am sure he would refuse my request.'

The future was to show that my distrust was justified. Narrow mindedness

and petty jealousy prevail everywhere alike.

I decide to help myself to this book, which I should never get by

asking. This is the half-holiday. The science master will not put in an

appearance today; and the key of my room is practically the same as his.

I go, with eyes and ears on the alert. My key does not quite fit; it

sticks a little, then goes in; and an extra effort makes it turn in

the lock. The door opens. I inspect the cupboard and find that it does

contain an algebra book, one of the big, fat books which men used to

write in those days, a book nearly half a foot thick. My legs give way

beneath me. You poor specimen of a housebreaker, suppose you were caught

at it! However, all goes well. Quick, let's lock the door again and go

back to our own quarters with the pilfered volume.

And now we are together, O mysterious tome, whose Arab name breathes a

strange mustiness of occult lore and claims kindred with the sciences of

almagest and alchemy. What will you show me? Let us turn the leaves at

random. Before fixing one's eyes on a definite point in the landscape,

it is well to take a summary view of the whole. Page follows swiftly

upon page, telling me nothing. A chapter catches my attention in the

middle of the volume; it is headed, Newton's Binomial Theorem.

The title allures me. What can a binomial theorem be, especially one

whose author is Newton, the great English mathematician who weighed the

worlds? What has the mechanism of the sky to do with this? Let us read

and seek for enlightenment. With my elbows on the table and my thumbs

behind my ears, I concentrate all my attention.

I am seized with astonishment, for I understand! There are a certain

number of letters, general symbols which are grouped in all manner of

ways, taking their places here, there and elsewhere by turns; there are,

as the text tells me, arrangements, permutations and combinations.

Pen in hand, I arrange, permute and combine. It is a very diverting

exercise, upon my word, a game in which the test of the written result

confirms the anticipations of logic and supplements the shortcomings of

one's thinking apparatus.

'It will be plain sailing,' said I to myself, 'if algebra is no more

difficult than this.'

I was to recover from the illusion later, when the binomial theorem,

that light, crisp biscuit, was followed by heavier and less

digestible fare. But, for the moment, I had no foretaste of the

future difficulties, of the pitfall in which one becomes more and more

entangled, the longer one persists in struggling. What a delightful

afternoon that was, before my grate, amid my permutations and

combinations! By the evening, I had nearly mastered my subject. When the

bell rang, at seven, to summon us to the common meal at the principal's

table, I went downstairs puffed up with the joys of the newly initiated

neophyte. I was escorted on my way by a, b and c, intertwined in cunning

garlands.

Next day, my pupil is there. Blackboard and chalk, everything is ready.

Not quite so ready is the master. I bravely broach my binomial theorem.

My hearer becomes interested in the combinations of letters. Not for a

moment does he suspect that I am putting the cart before the horse and

beginning where we ought to have finished. I relieve the dryness of my

explanations with a few little problems, so many halts at which the mind

takes breath awhile and gathers strength for fresh flights.

We try together. Discreetly, so as to leave him the merit of the

discovery, I shed a little light on the path. The solution is found. My

pupil triumphs; so do I, but silently, in my inner consciousness, which

says:

'You understand, because you succeed in making another understand.'

The hour passed quickly and very pleasantly for both of us. My young man

was contented when he left me; and I no less so, for I perceived a new

and original way of learning things.

The ingenious and easy arrangement of the binomial gave me time to

tackle my algebra book from the proper commencement. In three or four

days, I had rubbed up my weapons. There was nothing to be said about

addition and subtraction: they were so simple as to force themselves

upon one at first sight. Multiplication spoilt things. There was a

certain rule of signs which declared that minus multiplied by minus made

plus. How I toiled over that wretched paradox! It would seem that

the book did not explain this subject clearly, or rather employed too

abstract a method. I read, reread and meditated in vain: the obscure

text retained all its obscurity. That is the drawback of books in

general: they tell you what is printed in them and nothing more. If

you fail to understand, they never advise you, never suggest an attempt

along another road which might lead you to the light. The merest word

would sometimes be enough to put you on the right track; and that word

the books, hidebound in a regulation phraseology, never give you.

How greatly preferable is the oral lesson! It goes forward, goes back,

starts afresh, walks around the obstacle and varies the methods of

attack until, at long last, light is shed upon the darkness. This

incomparable beacon of the master's word was what I lacked; and I went

under, without hope of succor, in that treacherous pool of the rule of

signs.

My pupil was bound to suffer the effects. After an attempt at an

explanation in which I made the most of the few gleams that reached me I

asked him:

'Do you understand?'

It was a futile question, but useful for gaining time. Myself not

understanding, I was convinced beforehand that he did not understand

either.

'No,' he replied, accusing himself, perhaps, in his simple mind, of

possessing a brain incapable of taking in those transcendental verities.

'Let us try another method.'

And I start again this way and that way and yet another way. My pupil's

eyes serve as my thermometer and tell me of the progress of my efforts.

A blink of satisfaction announces my success. I have struck home, I have

found the joint in the armor. The product of minus multiplied by minus

delivers its mysteries to us.

And thus we continued our studies: he, the passive receiver, taking in

the ideas acquired without effort; I, the fierce pioneer, blasting my

rock, the book, with the aid of much sitting up at night, to extract the

diamond, truth. Another and no less arduous task fell to my share: I had

to cut and polish the recondite gem, to strip it of its ruggedness

and present it to my companion's intelligence under a less forbidding

aspect. This diamond cutter's work, which admitted a little light into

the precious stone, was the favorite occupation of my leisure; and I owe

a great deal to it.

The ultimate result was that my pupil passed his examination. As for the

book borrowed by stealth, I restored it to the shelves and replaced it

by another, which, this time, belonged to me.

At my normal school, I had learnt a little elementary geometry under

a master. From the first few lessons onwards, I rather enjoyed the

subject. I divined in it a guide for one's reasoning faculties through

the thickets of the imagination; I caught a glimpse of a search after

truth that did not involve too much stumbling on the way, because each

step forward rests solidly upon the step already taken; I suspected

geometry to be what it preeminently is: a school of intellectual

fencing.

The truth demonstrated and its application matter little to me; what

rouses my enthusiasm is the process that sets the truth before us.

We start from a brilliantly lighted spot and gradually get deeper and

deeper in the darkness, which, in its turn, becomes self-illuminated by

kindling new lights for a higher ascent. This progressive march of

the known toward the unknown, this conscientious lantern lighting what

follows by the rays of what comes before: that was my real business.

Geometry was to teach me the logical progression of thought; it was

to tell me how the difficulties are broken up into sections which,

elucidated consecutively, together form a lever capable of moving the

block that resists any direct efforts; lastly, it showed me how order is

engendered, order, the base of clarity. If it has ever fallen to my lot

to write a page or two which the reader has run over without excessive

fatigue, I owe it, in great part, to geometry, that wonderful teacher

of the art of directing one's thought. True, it does not bestow

imagination, a delicate flower blossoming none knows how and unable to

thrive on every soil; but it arranges what is confused, thins out the

dense, calms the tumultuous, filters the muddy and gives lucidity, a

superior product to all the tropes of rhetoric.

Yes, as a toiler with the pen, I owe much to it. Wherefore my thoughts

readily turn back to those bright hours of my novitiate, when, retiring

to a corner of the garden in recreation time, with a bit of paper on my

knees and a stump of pencil in my fingers, I used to practice deducing

this or that property correctly from an assemblage of straight lines.

The others amused themselves all around me; I found my delight in the

frustum of a pyramid. Perhaps I should have done better to strengthen

the muscles of my thighs by jumping and leaping, to increase the

suppleness of my loins with gymnastic contortions. I have known some

contortionists who have prospered beyond the thinker.

See me then entering the lists as an instructor of youth, fairly well

acquainted with the elements of geometry. In case of need, I could

handle the land surveyor's stake and chain. There my views ended. To

cube the trunk of a tree, to gauge a cask, to measure the distance of an

inaccessible point appeared to me the highest pitch to which geometrical

knowledge could hope to soar. Were there loftier flights? I did not even

suspect it, when an unexpected glimpse showed me the puny dimensions of

the little corner which I had cleared in the measureless domain.

At that time, the college in which, two years before, I had made my

first appearance as a teacher, had just halved the size of its classes

and largely increased its staff. The newcomers all lived in the

building, like myself, and we had our meals in common at the principal's

table. We formed a hive where, in our leisure time, some of us, in our

respective cells, worked up the honey of algebra and geometry, history

and physics, Greek and Latin most of all, sometimes with a view to the

class above, sometimes and oftener with a view to acquiring a degree.

The university titles lacked variety. All my colleagues were bachelors

of letters, but nothing more. They must, if possible, arm themselves

a little better to make their way in the world. We all worked hard and

steadily. I was the youngest of the industrious community and no less

eager than the rest to increase my modest equipment.

Visits between the different rooms were frequent. We would come to

consult one another about a difficulty, or simply to pass the time

of day. I had as a neighbor, in the next cell to mine, a retired

quartermaster who, weary of barrack life, had taken refuge in education.

When in charge of the books of his company he had become more or less

familiar with figures; and it became his ambition to take a mathematical

degree. His cerebrum appears to have hardened while he was with his

regiment. According to my dear colleagues, those amiable retailers

of the misfortunes of others, he had already twice been plucked.

Stubbornly, he returned to his books and exercises, refusing to be

daunted by two reverses.

It was not that he was allured by the beauties of mathematics, far from

it; but the step to which he aspired favored his plans. He hoped to

have his own boarders and dispense butter and vegetables to lucrative

purpose. The lover of study for its own sake and the persistent trapper

hunting a diploma as he would something to put in his mouth were not

made to understand or to see much of each other. Chance, however,

brought us together.

I had often surprised our friend sitting in the evening, by the light of

a candle, with his elbows on the table and his head between his hands,

meditating at great length in front of a big exercise book crammed with

cabalistic signs. From time to time, when an idea came to him, he would

take his pen and hastily put down a line of writing wherein letters,

large and small, were grouped without any grammatical sense. The letters

x and y often recurred, intermingled with figures. Every row ended

with the sign of equality and a nought. Next came more reflection, with

closed eyes, and a fresh row of letters arranged in a different order

and likewise followed by a nought. Page after page was filled in this

queer fashion, each line winding up with 0.

'What are you doing with all those rows of figures amounting to zero?' I

asked him one day.

The mathematician gave me a leery look, picked up in barracks. A

sarcastic droop in the corner of his eye showed how he pitied my

ignorance. My colleague of the many noughts did not, however, take an

unfair advantage of his superiority. He told me that he was working at

analytical geometry.

The phrase had a strange effect upon me. I ruminated silently to this

purpose: there was a higher geometry, which you learnt more particularly

with combinations of letters in which x and y played a prominent part.

When my next-door neighbor reflected so long, clutching his forehead

between his hands, he was trying to discover the hidden meaning of his

own hieroglyphics; he saw the ghostly translation of his sums dancing in

space. What did he perceive? How would the alphabetical signs, arranged

first in one and then in another manner, give an image of the actual

things, an image visible to the eyes of the mind alone? It beat me.

'I shall have to learn analytical geometry some day,' I said. 'Will you

help me?'

'I'm quite willing,' he replied, with a smile in which I read his lack

of confidence in my determination.

No matter; we struck a bargain that same evening. We would together

break up the stubble of algebra and analytical geometry, the foundation

of the mathematical degree; we would make common stock: he would bring

long hours of calculation, I my youthful ardor. We would begin as soon

as I had finished with my arts degree, which was my main preoccupation

for the moment.

In those far off days it was the rule to make a little serious literary

study take precedence of science. You were expected to be familiar

with the great minds of antiquity, to converse with Horace and Virgil,

Theocritus and Plato, before touching the poisons of chemistry or the

levers of mechanics. The niceties of thought could only be the gainers

by these preparations. Life's exigencies, ever harsher as progress

afflicts us with its increasing needs, have changed all that. A fig for

correct language! Business before all!

This modern hurry would have suited my impatience. I confess that I

fumed against the regulation which forced Latin and Greek upon me before

allowing me to open up relations with the sine and cosine. Today, wiser,

ripened by age and experience, I am of a different opinion. I very much

regret that my modest literary studies were not more carefully conducted

and further prolonged. To fill up this enormous blank a little, I

respectfully returned, somewhat late in life, to those good old books

which are usually sold second-hand with their leaves hardly cut.

Venerable pages, annotated in pencil during the long evenings of my

youth, I have found you again and you are more than ever my friends. You

have taught me that an obligation rests upon whoever wields the pen: he

must have something to say that is capable of interesting us. When

the subject comes within the scope of natural science, the interest is

nearly always assured; the difficulty, the great difficulty, is to prune

it of its thorns and to present it under a prepossessing aspect. Truth,

they say, rises naked from a well. Agreed; but admit that she is all

the better for being decently clothed. She craves, if not the gaudy

furbelows borrowed from rhetoric's wardrobe, at least a vine leaf. The

geometers alone have the right to refuse her that modest garment; in

theorems, plainness suffices. The others, especially the naturalist, are

in duty bound to drape a gauze tunic more or less elegantly around her

waist.

Suppose I say: 'Baptiste, give me my slippers.'

I am expressing myself in plain language, a little poor in variants. I

know exactly what I am saying and my speech is understood.

Others--and they are numerous--contend that this rudimentary method is

the best in all things. They talk science to their readers as they might

talk slippers to Baptiste. Kaffir syntax does not shock them. Do not

speak to them of the value of a well selected term, set down in its

right place, still less of a lilting construction, sounding rather well.

Childish nonsense they call all that; the fiddling of a short sighted

mind!

Perhaps they are right: the Baptiste idiom is a great economizer of time

and trouble. This advantage does not tempt me; it seems to me that

an idea stands out better if expressed in lucid language, with sober

imagery. A suitable phrase, placed in its correct position and saying

without fuss the things we want to say, necessitates a choice, an often

laborious choice. There are drab words, the commonplaces of colloquial

speech; and there are, so to speak, colored words, which may be compared

with the brushstrokes strewing patches of light over the gray background

of a painting. How are we to find those picturesque words, those

striking features which arrest the attention? How are we to group them

into a language heedful of syntax and not displeasing to the ear?

I was taught nothing of this art. For that matter, is it ever taught

in the schools? I greatly doubt it. If the fire that runs through our

veins, if inspiration do not come to our aid, we shall flutter the pages

of the thesaurus in vain: the word for which we seek will refuse to

come. Then to what masters shall we have recourse to quicken and develop

the humble germ that is latent within us? To books.

As a boy, I was always an ardent reader; but the niceties of a

well-balanced style hardly interested me: I did not understand them. A

good deal later, when close upon fifteen, I began vaguely to see that

words have a physiognomy of their own. Some pleased me better than

others by the distinctness of their meaning and the resonance of their

rhythm; they produced a clearer image in my mind; after their fashion,

they gave me a picture of the object described. Colored by its adjective

and vivified by its verb, the name became a living reality: what it said

I saw. And thus, gradually, was the magic of words revealed to me, when

the chances of, my undirected reading placed a few easy standard pages

in my way.

The Life of the Fly; With Which are Interspersed Some Chapters of Autobiography · 第 12 / 20 章