CHAPTER II

MEMORABILIA MATHEMATICA

THE MACMILLAN COMPANY

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MEMORABILIA MATHEMATICA

OR

THE PHILOMATH’S QUOTATION-BOOK

BY

ROBERT EDOUARD MORITZ, PH. D., PH. N. D.

PROFESSOR OF MATHEMATICS IN THE UNIVERSITY OF WASHINGTON

New York

THE MACMILLAN COMPANY

1914

_All rights reserved_

COPYRIGHT, 1914, BY

ROBERT EDOUARD MORITZ

PREFACE

Every one knows that the fine phrase “God geometrizes” is

attributed to Plato, but few know where this famous passage is

found, or the exact words in which it was first expressed. Those

who, like the author, have spent hours and even days in the

search of the exact statements, or the exact references, of

similar famous passages, will not question the timeliness and

usefulness of a book whose distinct purpose it is to bring

together into a single volume exact quotations, with their exact

references, bearing on one of the most time-honored, and even

today the most active and most fruitful of all the sciences, the

queen-mother of all the sciences, that is, mathematics.

It is hoped that the present volume will prove indispensable to

every teacher of mathematics, to every writer on mathematics,

and that the student of mathematics and the related sciences

will find its perusal not only a source of pleasure but of

encouragement and inspiration as well. The layman will find it a

repository of useful information covering a field of knowledge

which, owing to the unfamiliar and hence repellant character

of the language employed by mathematicians, is peculiarly

inaccessible to the general reader. No technical processes or

technical facility is required to understand and appreciate the

wealth of ideas here set forth in the words of the world’s great

thinkers.

No labor has been spared to make the present volume worthy of a

place among collections of a like kind in other fields. Ten years

have been devoted to its preparation, years, which if they could

have been more profitably, could scarcely have been more

pleasurably employed. As a result there have been brought

together over one thousand more or less familiar passages

pertaining to mathematics, by poets, philosophers, historians,

statesmen, scientists, and mathematicians. These have been

gathered from over three hundred authors, and have been grouped

under twenty heads, and cross indexed under nearly seven hundred

topics.

The author’s original plan was to give foreign quotations both in

the original and in translation, but with the growth of material

this plan was abandoned as infeasible. It was thought to serve

the best interest of the greater number of English readers to

give translations only, while preserving the references to the

original sources, so that the student or critical reader may

readily consult the original of any given extract. In cases where

the translation is borrowed the translator’s name is inserted in

brackets [] immediately after the author’s name. Brackets are

also used to indicate inserted words or phrases made necessary to

bring out the context.

The absence of similar English works has made the author’s work

largely that of the pioneer. Rebière’s “Mathématiques et

Mathématiciens” and Ahrens’ “Scherz und Ernst in der Mathematik”

have indeed been frequently consulted but rather with a view to

avoid overlapping than to receive aid. Thus certain topics as the

correspondence of German and French mathematicians, so excellently

treated by Ahrens, have purposely been omitted. The repetitions

are limited to a small number of famous utterances whose absence

from a work of this kind could scarcely be defended on any grounds.

No one can be more keenly aware of the shortcomings of a work

than its author, for none can have so intimate an acquaintance

with it. Among those of the present work is its incompleteness,

but it should be borne in mind that incompleteness is a necessary

concomitant of every collection of whatever kind. Much less can

completeness be expected in a first collection, made by a single

individual, in his leisure hours, and in a field which is already

boundless and is yet expanding day by day. A collection of great

thoughts, even if complete today, would be incomplete tomorrow.

Again, if some authors are quoted more frequently than others of

greater fame and authority, the reason may be sought not only in

the fact that the writings of some authors peculiarly lent

themselves to quotation, a quality singularly absent in other

writers of the greatest merit and authority, but also in this,

that the greatest freedom has been exercised in the choice of

selections. The author has followed the bent of his own fancy in

collecting whatever seemed to him sufficiently valuable because

of its content, its beauty, its originality, or its terseness, to

deserve a place in a “Memorabilia.”

Great pains has been taken to furnish exact readings and

references. In some cases where a passage could not be traced to

its first source, the secondary source has been given rather than

the reputed source. For the same reason many references are to

later editions rather than to inaccessible first editions.

The author feels confident that this work will be of assistance

to his co-workers in the field of mathematics and allied fields.

If in addition it should aid in a better appreciation of

mathematicians and their work on the part of laymen and students

in other fields, the author’s foremost aim in the preparation of

this work will have been achieved.

ROBERT EDOUARD MORITZ,

_September, 1913_.

CONTENTS

CHAPTER PAGE

I. DEFINITIONS AND OBJECT OF MATHEMATICS 1

II. THE NATURE OF MATHEMATICS 10

III. ESTIMATES OF MATHEMATICS 39

IV. THE VALUE OF MATHEMATICS 49

V. THE TEACHING OF MATHEMATICS 72

VI. STUDY AND RESEARCH IN MATHEMATICS 86

VII. MODERN MATHEMATICS 108

VIII. THE MATHEMATICIAN 121

IX. PERSONS AND ANECDOTES (A-M) 135

X. PERSONS AND ANECDOTES (N-Z) 166

XI. MATHEMATICS AS A FINE ART 181

XII. MATHEMATICS AS A LANGUAGE 194

XIII. MATHEMATICS AND LOGIC 201

XIV. MATHEMATICS AND PHILOSOPHY 209

XV. MATHEMATICS AND SCIENCE 224

XVI. ARITHMETIC 261

XVII. ALGEBRA 275

XVIII. GEOMETRY 292

XIX. THE CALCULUS AND ALLIED TOPICS 323

XX. THE FUNDAMENTAL CONCEPTS OF TIME AND SPACE 345

XXI. PARADOXES AND CURIOSITIES 364

INDEX 385

Alles Gescheite ist schon gedacht worden; man muss nur

versuchen, es noch einmal zu denken.--GOETHE.

_Sprüche in Prosa, Ethisches, I. 1._

A great man quotes bravely, and will not draw on his

invention when his memory serves him with a word as

good.--EMERSON.

_Letters and Social Aims, Quotation and

Originality._

MEMORABILIA MATHEMATICA

MEMORABILIA MATHEMATICA

CHAPTER I

DEFINITIONS AND OBJECT OF MATHEMATICS

=101.= I think it would be desirable that this form of word

[mathematics] should be reserved for the applications of the

science, and that we should use mathematic in the singular to

denote the science itself, in the same way as we speak of logic,

rhetoric, or (own sister to algebra) music.--SYLVESTER, J. J.

_Presidential Address to the British

Association, Exeter British Association

Report (1869); Collected Mathematical

Papers, Vol. 2, p. 659._

=102.= ... all the sciences which have for their end

investigations concerning order and measure, are related to

mathematics, it being of small importance whether this measure be

sought in numbers, forms, stars, sounds, or any other object;

that, accordingly, there ought to exist a general science which

should explain all that can be known about order and measure,

considered independently of any application to a particular

subject, and that, indeed, this science has its own proper name,

consecrated by long usage, to wit, _mathematics_. And a proof

that it far surpasses in facility and importance the sciences

which depend upon it is that it embraces at once all the objects

to which these are devoted and a great many others besides; ....

--DESCARTES.

_Rules for the Direction of the Mind,

Philosophy of D. [Torrey] (New York,

1892), p. 72._

=103.= [Mathematics] has for its object the _indirect_

measurement of magnitudes, and it _purposes to determine

magnitudes by each other, according to the precise relations

which exist between them_.--COMTE.

_Positive Philosophy [Martineau], Bk. 1,

chap. 1._

=104.= The business of concrete mathematics is to discover the

equations which express the mathematical laws of the phenomenon

under consideration; and these equations are the starting-point

of the calculus, which must obtain from them certain quantities

by means of others.--COMTE.

_Positive Philosophy [Martineau], Bk. 1,

chap. 2._

=105.= Mathematics is the science of the connection of

magnitudes. Magnitude is anything that can be put equal or

unequal to another thing. Two things are equal when in every

assertion each may be replaced by the other.--GRASSMANN, HERMANN.

_Stücke aus dem Lehrbuche der

Arithmetik, Werke (Leipzig, 1904), Bd.

2, p. 298._

=106.= Mathematic is either Pure or Mixed: To Pure Mathematic

belong those sciences which handle Quantity entirely severed from

matter and from axioms of natural philosophy. These are two,

Geometry and Arithmetic; the one handling quantity continued, the

other dissevered.... Mixed Mathematic has for its subject some

axioms and parts of natural philosophy, and considers quantity in

so far as it assists to explain, demonstrate and actuate these.

--BACON, FRANCIS.

_De Augmentis, Bk. 3; Advancement of

Learning, Bk. 2._

=107.= The ideas which these sciences, Geometry, Theoretical

Arithmetic and Algebra involve extend to all objects and changes

which we observe in the external world; and hence the consideration

of mathematical relations forms a large portion of many of the

sciences which treat of the phenomena and laws of external nature,

as Astronomy, Optics, and Mechanics. Such sciences are hence often

termed _Mixed Mathematics_, the relations of space and number

being, in these branches of knowledge, combined with principles

collected from special observation; while Geometry, Algebra, and

the like subjects, which involve no result of experience, are

called _Pure Mathematics_.--WHEWELL, WILLIAM.

_The Philosophy of the Inductive

Sciences, Part 1, Bk. 2, chap. I, sect.

4. (London, 1858)._

=108.= Higher Mathematics is the art of reasoning about numerical

relations between natural phenomena; and the several sections of

Higher Mathematics are different modes of viewing these

relations.--MELLOR, J. W.

_Higher Mathematics for Students of

Chemistry and Physics (New York, 1902),

Prologue._

=109.= Number, place, and combination ... the three intersecting

but distinct spheres of thought to which all mathematical ideas

admit of being referred.--SYLVESTER, J. J.

_Philosophical Magazine, Vol. 24 (1844),

p. 285; Collected Mathematical Papers,

Vol. 1, p. 91._

=110.= There are three ruling ideas, three so to say, spheres of

thought, which pervade the whole body of mathematical science, to

some one or other of which, or to two or all three of them

combined, every mathematical truth admits of being referred;

these are the three cardinal notions, of Number, Space and Order.

Arithmetic has for its object the properties of number in the

abstract. In algebra, viewed as a science of operations, order is

the predominating idea. The business of geometry is with the

evolution of the properties of space, or of bodies viewed as

existing in space.--SYLVESTER, J. J.

_A Probationary Lecture on Geometry,

York British Association Report (1844),

Part 2; Collected Mathematical Papers,

Vol. 2, p. 5._

=111.= The object of pure mathematics is those relations which

may be conceptually established among any conceived elements

whatsoever by assuming them contained in some ordered manifold;

the law of order of this manifold must be subject to our choice;

the latter is the case in both of the only conceivable kinds of

manifolds, in the discrete as well as in the continuous.

--PAPPERITZ, E.

_Über das System der rein mathematischen

Wissenschaften, Jahresbericht der

Deutschen Mathematiker-Vereinigung, Bd.

1, p. 36._

=112.= Pure mathematics is not concerned with magnitude. It is

merely the doctrine of notation of relatively ordered thought

operations which have become mechanical.--NOVALIS.

_Schriften (Berlin, 1901), Zweiter Teil,

p. 282._

=113.= Any conception which is definitely and completely determined

by means of a finite number of specifications, say by assigning a

finite number of elements, is a mathematical conception. Mathematics

has for its function to develop the consequences involved in the

definition of a group of mathematical conceptions. Interdependence

and mutual logical consistency among the members of the group are

postulated, otherwise the group would either have to be treated as

several distinct groups, or would lie beyond the sphere of

mathematics.--CHRYSTAL, GEORGE.

_Encyclopedia Britannica (9th edition),

Article “Mathematics.”_

=114.= The purely formal sciences, logic and mathematics, deal

with those relations which are, or can be, independent of the

particular content or the substance of objects. To mathematics in

particular fall those relations between objects which involve the

concepts of magnitude, of measure and of number.--HANKEL, HERMANN.

_Theorie der Complexen Zahlensysteme,

(Leipzig, 1867), p. 1._

=115.= _Quantity is that which is operated with according to

fixed mutually consistent laws._ Both operator and operand must

derive their meaning from the laws of operation. In the case of

ordinary algebra these are the three laws already indicated [the

commutative, associative, and distributive laws], in the algebra

of quaternions the same save the law of commutation for

multiplication and division, and so on. It may be questioned

whether this definition is sufficient, and it may be objected

that it is vague; but the reader will do well to reflect that any

definition must include the linear algebras of Peirce, the

algebra of logic, and others that may be easily imagined,

although they have not yet been developed. This general

definition of quantity enables us to see how operators may be

treated as quantities, and thus to understand the rationale of

the so called symbolical methods.--CHRYSTAL, GEORGE.

_Encyclopedia Britannica (9th edition),

Article “Mathematics.”_

=116.= Mathematics--in a strict sense--is the abstract science

which investigates deductively the conclusions implicit in the

elementary conceptions of spatial and numerical relations.

--MURRAY, J. A. H.

_A New English Dictionary._

=117.= Everything that the greatest minds of all times have

accomplished toward the _comprehension of forms_ by means of

concepts is gathered into one great science, _mathematics_.

--HERBART, J. F.

_Pestalozzi’s Idee eines A B C der

Anschauung, Werke [Kehrbach],

(Langensalza, 1890), Bd. 1, p. 163._

=118.= Perhaps the least inadequate description of the general scope

of modern Pure Mathematics--I will not call it a definition--would

be to say that it deals with _form_, in a very general sense of the

term; this would include algebraic form, functional relationship,

the relations of order in any ordered set of entities such as

numbers, and the analysis of the peculiarities of form of groups

of operations.--HOBSON, E. W.

_Presidential Address British

Association for the Advancement of

Science (1910); Nature, Vol. 84, p.

287._

=119.= The ideal of mathematics should be to erect a calculus to

facilitate reasoning in connection with every province of

thought, or of external experience, in which the succession of

thoughts, or of events can be definitely ascertained and

precisely stated. So that all serious thought which is not

philosophy, or inductive reasoning, or imaginative literature,

shall be mathematics developed by means of a calculus.

--WHITEHEAD, A. N.

_Universal Algebra (Cambridge, 1898),

Preface._

=120.= Mathematics is the science which draws necessary

conclusions.--PEIRCE, BENJAMIN.

_Linear Associative Algebra, American

Journal of Mathematics, Vol. 4 (1881),

p. 97._

=121.= Mathematics is the universal art apodictic.--SMITH, W. B.

_Quoted by Keyser, C. J. in Lectures on

Science, Philosophy and Art (New York,

1908), p. 13._

=122.= Mathematics in its widest signification is the development

of all types of formal, necessary, deductive reasoning.

--WHITEHEAD, A. N.

_Universal Algebra (Cambridge, 1898),

Preface, p. vi._

=123.= Mathematics in general is fundamentally the science of

self-evident things.--KLEIN, FELIX.

_Anwendung der Differential- und

Integralrechnung auf Geometrie (Leipzig,

1902), p. 26._

=124.= A mathematical science is any body of propositions which

is capable of an abstract formulation and arrangement in such a

way that every proposition of the set after a certain one is a

formal logical consequence of some or all the preceding

propositions. Mathematics consists of all such mathematical

sciences.--YOUNG, CHARLES WESLEY.

_Fundamental Concepts of Algebra and

Geometry (New York, 1911), p. 222._

=125.= Pure mathematics is a collection of hypothetical,

deductive theories, each consisting of a definite system of

primitive, _undefined_, concepts or symbols and primitive,

_unproved_, but self-consistent assumptions (commonly called

axioms) together with their logically deducible consequences

following by rigidly deductive processes without appeal to

intuition.--FITCH, G. D.

_The Fourth Dimension simply Explained

(New York, 1910), p. 58._

=126.= The whole of Mathematics consists in the organization of a

series of aids to the imagination in the process of reasoning.

--WHITEHEAD, A. N.

_Universal Algebra (Cambridge, 1898), p.

12._

=127.= Pure mathematics consists entirely of such asseverations

as that, if such and such a proposition is true of _anything_,

then such and such another proposition is true of that thing. It

is essential not to discuss whether the first proposition is

really true, and not to mention what the anything is of which it

is supposed to be true.... If our hypothesis is about _anything_

and not about some one or more particular things, then our

deductions constitute mathematics. Thus mathematics may be

defined as the subject in which we never know what we are talking

about, nor whether what we are saying is true.--RUSSELL, BERTRAND.

_Recent Work on the Principles of

Mathematics, International Monthly, Vol.

4 (1901), p. 84._

=128.= Pure Mathematics is the class of all propositions of the form

“_p_ implies _q_,” where _p_ and _q_ are propositions containing one

or more variables, the same in the two propositions, and neither _p_

nor _q_ contains any constants except logical constants. And logical

constants are all notions definable in terms of the following:

Implication, the relation of a term to a class of which it is a

member, the notion of _such that_, the notion of relation, and

such further notions as may be involved in the general notion of

propositions of the above form. In addition to these, Mathematics

_uses_ a notion which is not a constituent of the propositions

which it considers--namely, the notion of truth.--RUSSELL, BERTRAND.

_Principles of Mathematics (Cambridge,

1903), p. 1._

=129.= The object of pure Physic is the unfolding of the laws of

the intelligible world; the object of pure Mathematic that of

unfolding the laws of human intelligence.--SYLVESTER, J. J.

_On a theorem, connected with Newton’s

Rule, etc., Collected Mathematical

Papers, Vol. 3, p. 424._

=130.= First of all, we ought to observe, that mathematical

propositions, properly so called, are always judgments _a

priori,_ and not empirical, because they carry along with them

necessity, which can never be deduced from experience. If people

should object to this, I am quite willing to confine my

statements to pure mathematics, the very concept of which implies

that it does not contain empirical, but only pure knowledge _a

priori_.--KANT, IMMANUEL.

_Critique of Pure Reason [Müller], (New

York, 1900), p. 720._

=131.= Mathematics, the science of the ideal, becomes the means

of investigating, understanding and making known the world of the

real. The complex is expressed in terms of the simple. From one

point of view mathematics may be defined as the science of

successive substitutions of simpler concepts for more complex....

--WHITE, WILLIAM F.

_A Scrap-book of Elementary Mathematics,

(Chicago, 1908), p. 215._

=132.= The critical mathematician has abandoned the search for

truth. He no longer flatters himself that his propositions are or

can be known to him or to any other human being to be true;

and he contents himself with aiming at the correct, or the

consistent. The distinction is not annulled nor even blurred by

the reflection that consistency contains immanently a kind of

truth. He is not absolutely certain, but he believes profoundly

that it is possible to find various sets of a few propositions

each such that the propositions of each set are compatible, that

the propositions of each such set imply other propositions, and

that the latter can be deduced from the former with certainty.

That is to say, he believes that there are systems of coherent or

consistent propositions, and he regards it his business to

discover such systems. Any such system is a branch of mathematics.

--KEYSER, C. J.

_Science, New Series, Vol. 35, p. 107._

=133.= [Mathematics is] the study of ideal constructions (often

applicable to real problems), and the discovery thereby of

relations between the parts of these constructions, before

unknown.--PEIRCE, C. S.

_Century Dictionary, Article

“Mathematics.”_

=134.= Mathematics is that form of intelligence in which we bring

the objects of the phenomenal world under the control of the

conception of quantity. [Provisional definition.]--HOWISON, G. H.

_The Departments of Mathematics, and

their Mutual Relations; Journal of

Speculative Philosophy, Vol. 5, p. 164._

=135.= Mathematics is the science of the functional laws and

transformations which enable us to convert figured extension and

rated motion into number.--HOWISON, G. H.

_The Departments of Mathematics, and

their Mutual Relations; Journal of

Speculative Philosophy, Vol. 5, p. 170._

CHAPTER II

THE NATURE OF MATHEMATICS

=201.= Mathematics, from the earliest times to which the history

of human reason can reach, has followed, among that wonderful

people of the Greeks, the safe way of science. But it must not be

supposed that it was as easy for mathematics as for logic, in

which reason is concerned with itself alone, to find, or rather

to make for itself that royal road. I believe, on the contrary,

that there was a long period of tentative work (chiefly still

among the Egyptians), and that the change is to be ascribed to a

_revolution_, produced by the happy thought of a single man,

whose experiments pointed unmistakably to the path that had to be

followed, and opened and traced out for the most distant times

the safe way of a science. The history of that intellectual

revolution, which was far more important than the passage round

the celebrated Cape of Good Hope, and the name of its fortunate

author, have not been preserved to us.... A new light flashed on

the first man who demonstrated the properties of the isosceles

triangle (whether his name was _Thales_ or any other name), for

he found that he had not to investigate what he saw in the

figure, or the mere concepts of that figure, and thus to learn

its properties; but that he had to produce (by construction) what

he had himself, according to concepts _a priori_, placed into

that figure and represented in it, so that, in order to know

anything with certainty _a priori_, he must not attribute to that

figure anything beyond what necessarily follows from what he has

himself placed into it, in accordance with the concept.

--KANT, IMMANUEL.

_Critique of Pure Reason, Preface to the

Second Edition [Müller], (New York,

1900), p. 690._

=202.= [When followed in the proper spirit], there is no study in

the world which brings into more harmonious action all the

faculties of the mind than the one [mathematics] of which I

stand here as the humble representative and advocate. There is

none other which prepares so many agreeable surprises for its

followers, more wonderful than the transformation scene of a

pantomime, or, like this, seems to raise them, by successive

steps of initiation to higher and higher states of conscious

intellectual being.--SYLVESTER, J. J.

_A Plea for the Mathematician, Nature,

Vol. 1, p. 261._

=203.= Thought-economy is most highly developed in mathematics,

that science which has reached the highest formal development,

and on which natural science so frequently calls for assistance.

Strange as it may seem, the strength of mathematics lies in the

avoidance of all unnecessary thoughts, in the utmost economy of

thought-operations. The symbols of order, which we call numbers,

form already a system of wonderful simplicity and economy. When

in the multiplication of a number with several digits we employ

the multiplication table and thus make use of previously

accomplished results rather than to repeat them each time, when

by the use of tables of logarithms we avoid new numerical

calculations by replacing them by others long since performed,

when we employ determinants instead of carrying through from the

beginning the solution of a system of equations, when we

decompose new integral expressions into others that are

familiar,--we see in all this but a faint reflection of the

intellectual activity of a _Lagrange_ or _Cauchy_, who with the

keen discernment of a military commander marshalls a whole troop

of completed operations in the execution of a new one.--MACH, E.

_Populär-wissenschafliche Vorlesungen

(1908), pp. 224-225._

=204.= Pure mathematics proves itself a royal science both

through its content and form, which contains within itself the

cause of its being and its methods of proof. For in complete

independence mathematics creates for itself the object of which

it treats, its magnitudes and laws, its formulas and symbols.

--DILLMANN, E.

_Die Mathematik die Fackelträgerin einer

neuen Zeit (Stuttgart, 1889), p. 94._

=205.= The essence of mathematics lies in its freedom.

--CANTOR, GEORGE.

_Mathematische Annalen, Bd. 21, p. 564._

=206.= Mathematics pursues its own course unrestrained, not

indeed with an unbridled licence which submits to no laws, but

rather with the freedom which is determined by its own nature and

in conformity with its own being.--HANKEL, HERMANN.

_Die Entwickelung der Mathematik in den

letzten Jahrhunderten (Tübingen, 1884),

p. 16._

=207.= Mathematics is perfectly free in its development and is

subject only to the obvious consideration, that its concepts must

be free from contradictions in themselves, as well as definitely

and orderly related by means of definitions to the previously

existing and established concepts.--CANTOR, GEORGE.

_Grundlagen einer allgemeinen

Manigfaltigkeitslehre (Leipzig, 1883),

Sect. 8._

=208.= Mathematicians assume the right to choose, within the

limits of logical contradiction, what path they please in

reaching their results.--ADAMS, HENRY.

_A Letter to American Teachers of

History (Washington, 1910),

Introduction, p. v._

=209.= Mathematics is the predominant science of our time; its

conquests grow daily, though without noise; he who does not

employ it for himself, will some day find it employed against

himself.--HERBART, J. F.

_Werke [Kehrbach] (Langensalza, 1890),

Bd. 5, p. 105._

=210.= Mathematics is not the discoverer of laws, for it is not

induction; neither is it the framer of theories, for it is not

hypothesis; but it is the judge over both, and it is the arbiter

to which each must refer its claims; and neither law can rule nor

theory explain without the sanction of mathematics.

--PEIRCE, BENJAMIN.

_Linear Associative Algebra, American

Journal of Mathematics, Vol. 4 (1881),

p. 97._

=211.= Mathematics is a science continually expanding; and its

growth, unlike some political and industrial events, is attended

by universal acclamation.--WHITE, H. S.

_Congress of Arts and Sciences (Boston

and New York, 1905), Vol. 1, p. 455._

=212.= Mathematics accomplishes really nothing outside of the

realm of magnitude; marvellous, however, is the skill with which

it masters magnitude wherever it finds it. We recall at once the

network of lines which it has spun about heavens and earth; the

system of lines to which azimuth and altitude, declination and

right ascension, longitude and latitude are referred; those

abscissas and ordinates, tangents and normals, circles of

curvature and evolutes; those trigonometric and logarithmic

functions which have been prepared in advance and await

application. A look at this apparatus is sufficient to show that

mathematicians are not magicians, but that everything is

accomplished by natural means; one is rather impressed by the

multitude of skilful machines, numerous witnesses of a manifold

and intensely active industry, admirably fitted for the

acquisition of true and lasting treasures.--HERBART, J. F.

_Werke [Kehrbach] (Langensalza, 1890),

Bd. 5, p. 101._

=213.= They [mathematicians] only take those things into

consideration, of which they have clear and distinct ideas,

designating them by proper, adequate, and invariable names, and

premising only a few axioms which are most noted and certain to

investigate their affections and draw conclusions from them, and

agreeably laying down a very few hypotheses, such as are in the

highest degree consonant with reason and not to be denied by

anyone in his right mind. In like manner they assign generations

or causes easy to be understood and readily admitted by all, they

preserve a most accurate order, every proposition immediately

following from what is supposed and proved before, and reject all

things howsoever specious and probable which can not be inferred

and deduced after the same manner.--BARROW, ISAAC.

_Mathematical Lectures (London, 1734),

p. 66._

=214.= The dexterous management of terms and being able to _fend_

and _prove_ with them, I know has and does pass in the world for

a great part of learning; but it is learning distinct from

knowledge, for knowledge consists only in perceiving the

habitudes and relations of ideas one to another, which is done

without words; the intervention of sounds helps nothing to it.

And hence we see that there is least use of distinction where

there is most knowledge: I mean in mathematics, where men have

determined ideas with known names to them; and so, there being no

room for equivocations, there is no need of distinctions.

--LOCKE, JOHN.

_Conduct of the Understanding, Sect.

31._

=215.= In mathematics it [sophistry] had no place from the

beginning: Mathematicians having had the wisdom to define

accurately the terms they use, and to lay down, as axioms, the

first principles on which their reasoning is grounded. Accordingly

we find no parties among mathematicians, and hardly any disputes.

--REID, THOMAS.

_Essays on the Intellectual Powers of

Man, Essay 1, chap. 1._

=216.= In most sciences one generation tears down what another

has built and what one has established another undoes. In

Mathematics alone each generation builds a new story to the old

structure.--HANKEL, HERMANN.

_Die Entwickelung der Mathematik in den

letzten Jahrhunderten (Tübingen, 1884),

p. 25._

=217.= Mathematics, the priestess of definiteness and

clearness.--HERBART, J. F.

_Werke [Kehrbach] (Langensalza, 1890),

Bd. 1, p. 171._

=218.= ... mathematical analysis is co-extensive with nature

itself, it defines all perceivable relations, measures times,

spaces, forces, temperatures; it is a difficult science which

forms but slowly, but preserves carefully every principle once

acquired; it increases and becomes stronger incessantly amidst

all the changes and errors of the human mind.

Its chief attribute is clearness; it has no means for expressing

confused ideas. It compares the most diverse phenomena and

discovers the secret analogies which unite them. If matter

escapes us, as that of air and light because of its extreme

tenuity, if bodies are placed far from us in the immensity of

space, if man wishes to know the aspect of the heavens at

successive periods separated by many centuries, if gravity and

heat act in the interior of the solid earth at depths which will

forever be inaccessible, mathematical analysis is still able to

trace the laws of these phenomena. It renders them present and

measurable, and appears to be the faculty of the human mind

destined to supplement the brevity of life and the imperfection

of the senses, and what is even more remarkable, it follows the

same course in the study of all phenomena; it explains them in

the same language, as if in witness to the unity and simplicity

of the plan of the universe, and to make more manifest the

unchangeable order which presides over all natural causes.

--FOURIER, J.

_Théorie Analytique de la Chaleur,

Discours Préliminaire._

=219.= Let us now declare the means whereby our understanding can

rise to knowledge without fear of error. There are two such

means: intuition and deduction. By intuition I mean not the

varying testimony of the senses, nor the deductive judgment of

imagination naturally extravagant, but the conception of an

attentive mind so distinct and so clear that no doubt remains to

it with regard to that which it comprehends; or, what amounts to

the same thing, the self-evidencing conception of a sound and

attentive mind, a conception which springs from the light of

reason alone, and is more certain, because more simple, than

deduction itself....

It may perhaps be asked why to intuition we add this other mode

of knowing, by deduction, that is to say, the process which, from

something of which we have certain knowledge, draws consequences

which necessarily follow therefrom. But we are obliged to admit

this second step; for there are a great many things which,

without being evident of themselves, nevertheless bear the

marks of certainty if only they are deduced from true and

incontestable principles by a continuous and uninterrupted

movement of thought, with distinct intuition of each thing; just

as we know that the last link of a long chain holds to the first,

although we can not take in with one glance of the eye the

intermediate links, provided that, after having run over them in

succession, we can recall them all, each as being joined to its

fellows, from the first up to the last. Thus we distinguish

intuition from deduction, inasmuch as in the latter case there is

conceived a certain progress or succession, while it is not so in

the former;... whence it follows that primary propositions,

derived immediately from principles, may be said to be known,

according to the way we view them, now by intuition, now by

deduction; although the principles themselves can be known only

by intuition, the remote consequences only by deduction.

--DESCARTES.

_Rules for the Direction of the Mind,

Philosophy of D. [Torrey] (New York,

1892), pp. 64, 65._

=220.= Analysis and natural philosophy owe their most important

discoveries to this fruitful means, which is called induction.

Newton was indebted to it for his theorem of the binomial and the

principle of universal gravity.--LAPLACE.

_A Philosophical Essay on Probabilities

[Truscott and Emory] (New York 1902), p.

176._

=221.= There is in every step of an arithmetical or algebraical

calculation a real induction, a real inference from facts to facts,

and what disguises the induction is simply its comprehensive

nature, and the consequent extreme generality of its language.

--MILL, J. S.

_System of Logic, Bk. 2, chap. 6, 2._

=222.= It would appear that Deductive and Demonstrative Sciences

are all, without exception, Inductive Sciences: that their

evidence is that of experience, but that they are also, in virtue

of the peculiar character of one indispensable portion of the

general formulae according to which their inductions are made,

Hypothetical Sciences. Their conclusions are true only upon

certain suppositions, which are, or ought to be, approximations

to the truth, but are seldom, if ever, exactly true; and to this

hypothetical character is to be ascribed the peculiar certainty,

which is supposed to be inherent in demonstration.--MILL, J. S.

_System of Logic, Bk. 2, chap. 6, 1._

=223.= The peculiar character of mathematical truth is, that it

is necessarily and inevitably true; and one of the most important

lessons which we learn from our mathematical studies is a

knowledge that there are such truths, and a familiarity with

their form and character.

This lesson is not only lost, but read backward, if the student

is taught that there is no such difference, and that mathematical

truths themselves are learned by experience.--WHEWELL, W.

_Thoughts on the Study of Mathematics.

Principles of English University

Education (London, 1838)._

=224.= These sciences, Geometry, Theoretical Arithmetic and Algebra,

have no principles besides definitions and axioms, and no process

of proof but _deduction_; this process, however, assuming a most

remarkable character; and exhibiting a combination of simplicity

and complexity, of rigour and generality, quite unparalleled in

other subjects.--WHEWELL, W.

_The Philosophy of the Inductive

Sciences, Part 1, Bk. 2, chap. 1, sect.

2 (London, 1858)._

=225.= The apodictic quality of mathematical thought, the certainty

and correctness of its conclusions, are due, not to a special mode

of ratiocination, but to the character of the concepts with which

it deals. What is that distinctive characteristic? I answer:

_precision_, _sharpness_, _completeness_,[1] of definition. But

how comes your mathematician by such completeness? There is no

mysterious trick involved; some ideas admit of such precision,

others do not; and the mathematician is one who deals with those

that do.--KEYSER, C. J.

_The Universe and Beyond; Hibbert

Journal, Vol. 3 (1904-1905), p. 309._

[1] i.e., in terms of the absolutely clear and

_in_definable.

=226.= The reasoning of mathematicians is founded on certain and

infallible principles. Every word they use conveys a determinate

idea, and by accurate definitions they excite the same ideas in

the mind of the reader that were in the mind of the writer. When

they have defined the terms they intend to make use of, they

premise a few axioms, or self-evident principles, that every one

must assent to as soon as proposed. They then take for granted

certain postulates, that no one can deny them, such as, that a

right line may be drawn from any given point to another, and from

these plain, simple principles they have raised most astonishing

speculations, and proved the extent of the human mind to be more

spacious and capacious than any other science.--ADAMS, JOHN.

_Diary, Works (Boston, 1850), Vol. 2, p.

21._

=227.= It may be observed of mathematicians that they only meddle

with such things as are certain, passing by those that are

doubtful and unknown. They profess not to know all things,

neither do they affect to speak of all things. What they know to

be true, and can make good by invincible arguments, that they

publish and insert among their theorems. Of other things they

are silent and pass no judgment at all, choosing rather to

acknowledge their ignorance, than affirm anything rashly. They

affirm nothing among their arguments or assertions which is not

most manifestly known and examined with utmost rigour, rejecting

all probable conjectures and little witticisms. They submit

nothing to authority, indulge no affection, detest subterfuges of

words, and declare their sentiments, as in a court of justice,

_without passion, without apology_; knowing that their reasons,

as Seneca testifies of them, are not brought to _persuade_, but

to compel.--BARROW, ISAAC.

_Mathematical Lectures (London, 1734),

p. 64._

=228.= What is exact about mathematics but exactness? And is not

this a consequence of the inner sense of truth?--GOETHE.

_Sprüche in Prosa, Natur, 6, 948._

=229.= ... the three positive characteristics that distinguish

mathematical knowledge from other knowledge ... may be briefly

expressed as follows: first, mathematical knowledge bears more

distinctly the imprint of truth on all its results than any other

kind of knowledge; secondly, it is always a sure preliminary step

to the attainment of other correct knowledge; thirdly, it has no

need of other knowledge.--SCHUBERT, H.

_Mathematical Essays and Recreations

(Chicago, 1898), p. 35._

=230.= It is now necessary to indicate more definitely the reason

why mathematics not only carries conviction in itself, but also

transmits conviction to the objects to which it is applied. The

reason is found, first of all, in the perfect precision with

which the elementary mathematical concepts are determined; in

this respect each science must look to its own salvation.... But

this is not all. As soon as human thought attempts long chains of

conclusions, or difficult matters generally, there arises not

only the danger of error but also the suspicion of error, because

since all details cannot be surveyed with clearness at the same

instant one must in the end be satisfied with a _belief_ that

nothing has been overlooked from the beginning. Every one knows

how much this is the case even in arithmetic, the most elementary

use of mathematics. No one would imagine that the higher parts of

mathematics fare better in this respect; on the contrary, in more

complicated conclusions the uncertainty and suspicion of hidden

errors increases in rapid progression. How does mathematics

manage to rid itself of this inconvenience which attaches to it

in the highest degree? By making proofs more rigorous? By giving

new rules according to which the old rules shall be applied? Not

in the least. A very great uncertainty continues to attach to the

result of each single computation. But there are checks. In the

realm of mathematics each point may be reached by a hundred

different ways; and if each of a hundred ways leads to the same

point, one may be sure that the right point has been reached. A

calculation without a check is as good as none. Just so it is

with every isolated proof in any speculative science whatever;

the proof may be ever so ingenious, and ever so perfectly true

and correct, it will still fail to convince permanently. He will

therefore be much deceived, who, in metaphysics, or in psychology

which depends on metaphysics, hopes to see his greatest care in

the precise determination of the concepts and in the logical

conclusions rewarded by conviction, much less by success in

transmitting conviction to others. Not only must the conclusions

support each other, without coercion or suspicion of subreption,

but in all matters originating in experience, or judging

concerning experience, the results of speculation must be

verified by experience, not only superficially, but in countless

special cases.--HERBART, J. F.

_Werke [Kehrbach] (Langensalza, 1890),

Bd. 5, p. 105._

=231.= [In mathematics] we behold the conscious logical activity

of the human mind in its purest and most perfect form. Here we

learn to realize the laborious nature of the process, the great

care with which it must proceed, the accuracy which is necessary

to determine the exact extent of the general propositions arrived

at, the difficulty of forming and comprehending abstract concepts;

but here we learn also to place confidence in the certainty, scope

and fruitfulness of such intellectual activity.--HELMHOLTZ, H.

_Ueber das Verhältniss der

Naturwissenschaften zur Gesammtheit der

Wissenschaft, Vorträge und Reden, Bd. 1

(1896), p. 176._

=232.= It is true that mathematics, owing to the fact that its

whole content is built up by means of purely logical deduction

from a small number of universally comprehended principles,

has not unfittingly been designated as the science of the

_self-evident_ [Selbstverständlichen]. Experience however, shows

that for the majority of the cultured, even of scientists,

mathematics remains the science of the _incomprehensible_

[Unverständlichen].--PRINGSHEIM, ALFRED.

_Ueber Wert und angeblichen Unwert der

Mathematik, Jahresbericht der Deutschen

Mathematiker Vereinigung (1904), p.

357._

=233.= Mathematical reasoning is deductive in the sense that it

is based upon definitions which, as far as the validity of the

reasoning is concerned (apart from any existential import), needs

only the test of self-consistency. Thus no external verification

of definitions is required in mathematics, as long as it is

considered merely as mathematics.--WHITEHEAD, A. N.

_Universal Algebra (Cambridge, 1898),

Preface, p. vi._

=234.= The mathematician pays not the least regard either to

testimony or conjecture, but deduces everything by demonstrative

reasoning, from his definitions and axioms. Indeed, whatever is

built upon conjecture, is improperly called science; for

conjecture may beget opinion, but cannot produce knowledge.

--REID, THOMAS.

_Essays on the Intellectual Powers of

Man, Essay 1, chap. 3._

=235.= ... for the saving the long progression of the thoughts to

remote and first principles in every case, the mind should

provide itself several stages; that is to say, intermediate

principles, which it might have recourse to in the examining

those positions that come in its way. These, though they are not

self-evident principles, yet, if they have been made out from

them by a wary and unquestionable deduction, may be depended on

as certain and infallible truths, and serve as unquestionable

truths to prove other points depending upon them, by a nearer and

shorter view than remote and general maxims.... And thus

mathematicians do, who do not in every new problem run it back to

the first axioms through all the whole train of intermediate

propositions. Certain theorems that they have settled to

themselves upon sure demonstration, serve to resolve to them

multitudes of propositions which depend on them, and are as

firmly made out from thence as if the mind went afresh over every

link of the whole chain that tie them to first self-evident

principles.--LOCKE, JOHN.

_The Conduct of the Understanding, Sect.

21._

=236.= Those intervening ideas, which serve to show the agreement

of any two others, are called _proofs_; and where the agreement or

disagreement is by this means plainly and clearly perceived, it is

called _demonstration_; it being _shown_ to the understanding, and

the mind made to see that it is so. A quickness in the mind to

find out these intermediate ideas, (that shall discover the

agreement or disagreement of any other) and to apply them right,

is, I suppose, that which is called _sagacity_.--LOCKE, JOHN.

_An Essay concerning Human

Understanding, Bk. 6, chaps. 2, 3._

=237.= ... the speculative propositions of mathematics do not

relate to _facts_; ... all that we are convinced of by any

demonstration in the science, is of a necessary connection

subsisting between certain suppositions and certain conclusions.

When we find these suppositions actually take place in a

particular instance, the demonstration forces us to apply the

conclusion. Thus, if I could form a triangle, the three sides of

which were accurately mathematical lines, I might affirm of this

individual figure, that its three angles are equal to two right

angles; but, as the imperfection of my senses puts it out of my

power to be, in any case, _certain_ of the exact correspondence

of the diagram which I delineate, with the definitions given in

the elements of geometry, I never can apply with confidence to a

particular figure, a mathematical theorem. On the other hand, it

appears from the daily testimony of our senses that the

speculative truths of geometry may be applied to material objects

with a degree of accuracy sufficient for the purposes of life;

and from such applications of them, advantages of the most

important kind have been gained to society.--STEWART, DUGALD.

_Elements of the Philosophy of the Human

Mind, Part 3, chap. 1, sect. 3._

=238.= No process of sound reasoning can establish a result not

contained in the premises.--MELLOR, J. W.

_Higher Mathematics for Students of

Chemistry and Physics (New York, 1902),

p. 2._

=239.= ... we cannot get more out of the mathematical mill than

we put into it, though we may get it in a form infinitely more

useful for our purpose.--HOPKINSON, JOHN.

_James Forrest Lecture, 1894._

=240.= The iron labor of conscious logical reasoning demands

great perseverance and great caution; it moves on but slowly, and

is rarely illuminated by brilliant flashes of genius. It knows

little of that facility with which the most varied instances come

thronging into the memory of the philologist or historian. Rather

is it an essential condition of the methodical progress of

mathematical reasoning that the mind should remain concentrated

on a single point, undisturbed alike by collateral ideas on the

one hand, and by wishes and hopes on the other, and moving on

steadily in the direction it has deliberately chosen.

--HELMHOLTZ, H.

_Ueber das Verhältniss der

Naturwissenschaften zur Gesammtheit der

Wissenschaft, Vorträge und Reden, Bd. 1

(1896), p. 178._

=241.= If it were always necessary to reduce everything to

intuitive knowledge, demonstration would often be insufferably

prolix. This is why mathematicians have had the cleverness to

divide the difficulties and to demonstrate separately the

intervening propositions. And there is art also in this; for as

the mediate truths (which are called _lemmas_, since they appear

to be a digression) may be assigned in many ways, it is well, in

order to aid the understanding and memory, to choose of them

those which greatly shorten the process, and appear memorable and

worthy in themselves of being demonstrated. But there is another

obstacle, viz.: that it is not easy to demonstrate all the

axioms, and to reduce demonstrations wholly to intuitive

knowledge. And if we had chosen to wait for that, perhaps we

should not yet have the science of geometry.--LEIBNITZ, G. W.

_New Essay on Human Understanding

[Langley], Bk. 4, chaps. 2, 8._

=242.= In Pure Mathematics, where all the various truths are

necessarily connected with each other, (being all necessarily

connected with those _hypotheses_ which are the principles of the

science), an arrangement is beautiful in proportion as the

principles are few; and what we admire perhaps chiefly in the

science, is the astonishing variety of consequences which may be

demonstrably deduced from so small a number of premises.

--STEWART, DUGALD.

_The Elements of the Philosophy of the

Human Mind, Part 3, chap. 1, sect. 3._

=243.= Whenever ... a controversy arises in mathematics, the

issue is not whether a thing is true or not, but whether the

proof might not be conducted more simply in some other way, or

whether the proposition demonstrated is sufficiently important

for the advancement of the science as to deserve especial

enunciation and emphasis, or finally, whether the proposition is

not a special case of some other and more general truth which is

as easily discovered.--SCHUBERT, H.

_Mathematical Essays and Recreations

(Chicago, 1898), p. 28._

=244.= ... just as the astronomer, the physicist, the geologist,

or other student of objective science looks about in the world of

sense, so, not metaphorically speaking but literally, the mind of

the mathematician goes forth in the universe of logic in quest of

the things that are there; exploring the heights and depths for

facts--ideas, classes, relationships, implications, and the rest;

observing the minute and elusive with the powerful microscope of

his Infinitesimal Analysis; observing the elusive and vast with

the limitless telescope of his Calculus of the Infinite; making

guesses regarding the order and internal harmony of the data

observed and collocated; testing the hypotheses, not merely by

the complete induction peculiar to mathematics, but, like his

colleagues of the outer world, resorting also to experimental tests

and incomplete induction; frequently finding it necessary, in view

of unforeseen disclosures, to abandon one hopeful hypothesis or to

transform it by retrenchment or by enlargement:--thus, in his own

domain, matching, point for point, the processes, methods and

experience familiar to the devotee of natural science.

--KEYSER, CASSIUS J.

_Lectures on Science, Philosophy and Art

(New York, 1908), p. 26._

=245.= That mathematics “do not cultivate the power of

generalization,” ... will be admitted by no person of competent

knowledge, except in a very qualified sense. The generalizations

of mathematics, are, no doubt, a different thing from the

generalizations of physical science; but in the difficulty of

seizing them, and the mental tension they require, they are no

contemptible preparation for the most arduous efforts of the

scientific mind. Even the fundamental notions of the higher

mathematics, from those of the differential calculus upwards are

products of a very high abstraction.... To perceive the

mathematical laws common to the results of many mathematical

operations, even in so simple a case as that of the binomial

theorem, involves a vigorous exercise of the same faculty which

gave us Kepler’s laws, and rose through those laws to the theory

of universal gravitation. Every process of what has been called

Universal Geometry--the great creation of Descartes and his

successors, in which a single train of reasoning solves whole

classes of problems at once, and others common to large groups

of them--is a practical lesson in the management of wide

generalizations, and abstraction of the points of agreement from

those of difference among objects of great and confusing

diversity, to which the purely inductive sciences cannot furnish

many superior. Even so elementary an operation as that of

abstracting from the particular configuration of the triangles or

other figures, and the relative situation of the particular lines

or points, in the diagram which aids the apprehension of a common

geometrical demonstration, is a very useful, and far from being

always an easy, exercise of the faculty of generalization so

strangely imagined to have no place or part in the processes of

mathematics.--MILL, JOHN STUART.

_An Examination of Sir William

Hamilton’s Philosophy (London, 1878),

pp. 612, 613._

=246.= When the greatest of American logicians, speaking of the

powers that constitute the born geometrician, had named

Conception, Imagination, and Generalization, he paused. Thereupon

from one of the audience there came the challenge, “What of

reason?” The instant response, not less just than brilliant, was:

“Ratiocination--that is but the smooth pavement on which the

chariot rolls.”--KEYSER, C. J.

_Lectures on Science, Philosophy and Art

(New York, 1908), p. 31._

=247.= ... the reasoning process [employed in mathematics] is not

different from that of any other branch of knowledge, ... but

there is required, and in a great degree, that attention of mind

which is in some part necessary for the acquisition of all

knowledge, and in this branch is indispensably necessary. This

must be given in its fullest intensity; ... the other elements

especially characteristic of a mathematical mind are quickness

in perceiving logical sequence, love of order, methodical

arrangement and harmony, distinctness of conception.--PRICE, B.

_Treatise on Infinitesimal Calculus

(Oxford, 1868), Vol. 3, p. 6._

=248.= Histories make men wise; poets, witty; the mathematics,

subtile; natural philosophy, deep; moral, grave; logic and

rhetoric, able to contend.--BACON, FRANCIS.

_Essays, Of Studies._

=249.= The Mathematician deals with two properties of objects

only, number and extension, and all the inductions he wants have

been formed and finished ages ago. He is now occupied with

nothing but deduction and verification.--HUXLEY, T. H.

_On the Educational Value of the Natural

History Sciences; Lay Sermons, Addresses

and Reviews; (New York, 1872), p. 87._

=250.= [Mathematics] is that [subject] which knows nothing of

observation, nothing of experiment, nothing of induction, nothing

of causation.--HUXLEY, T. H.

_The Scientific Aspects of Positivism,

Fortnightly Review (1898); Lay Sermons,

Addresses and Reviews, (New York, 1872),

p. 169._

=251.= We are told that “Mathematics is that study which knows

nothing of observation, nothing of experiment, nothing of induction,

nothing of causation.” I think no statement could have been made

more opposite to the facts of the case; that mathematical analysis

is constantly invoking the aid of new principles, new ideas, and

new methods, not capable of being defined by any form of words,

but springing direct from the inherent powers and activities of

the human mind, and from continually renewed introspection of that

inner world of thought of which the phenomena are as varied and

require as close attention to discern as those of the outer physical

world (to which the inner one in each individual man may, I think,

be conceived to stand somewhat in the same relation of correspondence

as a shadow to the object from which it is projected, or as the

hollow palm of one hand to the closed fist which it grasps of the

other), that it is unceasingly calling forth the faculties of

observation and comparison, that one of its principal weapons is

induction, that it has frequent recourse to experimental trial and

verification, and that it affords a boundless scope for the exercise

of the highest efforts of the imagination and invention.

--SYLVESTER, J. J.

_Presidential Address to British

Association, Exeter British Association

Report (1869), pp. 1-9.; Collected

Mathematical Papers, Vol. 2, p. 654._

=252.= The actual evolution of mathematical theories proceeds by a

process of induction strictly analogous to the method of induction

employed in building up the physical sciences; observation,

comparison, classification, trial, and generalisation are

essential in both cases. Not only are special results, obtained

independently of one another, frequently seen to be really

included in some generalisation, but branches of the subject

which have been developed quite independently of one another are

sometimes found to have connections which enable them to be

synthesised in one single body of doctrine. The essential nature

of mathematical thought manifests itself in the discernment of

fundamental identity in the mathematical aspects of what are

superficially very different domains. A striking example of this

species of immanent identity of mathematical form was exhibited by

the discovery of that distinguished mathematician ... Major MacMahon,

that all possible Latin squares are capable of enumeration by the

consideration of certain differential operators. Here we have a

case in which an enumeration, which appears to be not amenable to

direct treatment, can actually be carried out in a simple manner

when the underlying identity of the operation is recognised with

that involved in certain operations due to differential operators,

the calculus of which belongs superficially to a wholly different

region of thought from that relating to Latin squares.

--HOBSON, E. W.

_Presidential Address British

Association for the Advancement of

Science (1910); Nature, Vol. 84, p.

290._

=253.= It has been asserted ... that the power of observation is not

developed by mathematical studies; while the truth is, that; from

the most elementary mathematical notion that arises in the mind of

a child to the farthest verge to which mathematical investigation

has been pushed and applied, this power is in constant exercise.

By observation, as here used, can only be meant the fixing of the

attention upon objects (physical or mental) so as to note distinctive

peculiarities--to recognize resemblances, differences, and other

relations. Now the first mental act of the child recognizing the

distinction between _one_ and more than one, between _one_ and _two_,

_two_ and _three_, etc., is exactly this. So, again, the first

geometrical notions are as pure an exercise of this power as can be

given. To know a straight line, to distinguish it from a curve; to

recognize a triangle and distinguish the several forms--what are these,

and all perception of form, but a series of observations? Nor is it

alone in securing these fundamental conceptions of number and form that

observation plays so important a part. The very genius of the common

geometry as a method of reasoning--a system of investigation--is,

that it is but a series of observations. The figure being before the

eye in actual representation, or before the mind in conception, is so

closely scrutinized, that all its distinctive features are perceived;

auxiliary lines are drawn (the imagination leading in this), and a new

series of inspections is made; and thus, by means of direct, simple

observations, the investigation proceeds. So characteristic of common

geometry is this method of investigation, that Comte, perhaps the

ablest of all writers upon the philosophy of mathematics, is disposed

to class geometry, as to its method, with the natural sciences, being

based upon observation. Moreover, when we consider applied mathematics,

we need only to notice that the exercise of this faculty is so

essential, that the basis of all such reasoning, the very material

with which we build, have received the name _observations_. Thus we

might proceed to consider the whole range of the human faculties, and

find for the most of them ample scope for exercise in mathematical

studies. Certainly, the _memory_ will not be found to be neglected.

The very first steps in number--counting, the multiplication table,

etc., make heavy demands on this power; while the higher branches

require the memorizing of formulas which are simply appalling to the

uninitiated. So the _imagination_, the creative faculty of the mind,

has constant exercise in all original mathematical investigations,

from the solution of the simplest problems to the discovery of the

most recondite principle; for it is not by sure, consecutive steps,

as many suppose, that we advance from the known to the unknown. The

imagination, not the logical faculty, leads in this advance. In fact,

practical observation is often in advance of logical exposition.

Thus, in the discovery of truth, the imagination habitually presents

hypotheses, and observation supplies facts, which it may require ages

for the tardy reason to connect logically with the known. Of this

truth, mathematics, as well as all other sciences, affords abundant

illustrations. So remarkably true is this, that today it is seriously

questioned by the majority of thinkers, whether the sublimest branch of

mathematics,--the _infinitesimal calculus_--has anything more than an

empirical foundation, mathematicians themselves not being agreed as to

its logical basis. That the imagination, and not the logical faculty,

leads in all original investigation, no one who has ever succeeded in

producing an original demonstration of one of the simpler propositions

of geometry, can have any doubt. Nor are _induction_, _analogy_,

the _scrutinization_ of _premises_ or the _search_ for them, or the

_balancing_ of _probabilities_, spheres of mental operations foreign to

mathematics. No one, indeed, can claim pre-eminence for mathematical

studies in all these departments of intellectual culture, but it may,

perhaps, be claimed that scarcely any department of science affords

discipline to so great a number of faculties, and that none presents so

complete a gradation in the exercise of these faculties, from the first

principles of the science to the farthest extent of its applications,

as mathematics.--OLNEY, EDWARD.

_Kiddle and Schem’s Encyclopedia of

Education, (New York, 1877), Article

“Mathematics.”_

=254.= The opinion appears to be gaining ground that this very

general conception of functionality, born on mathematical ground,

is destined to supersede the narrower notion of causation,

traditional in connection with the natural sciences. As an

abstract formulation of the idea of determination in its most

general sense, the notion of functionality includes and

transcends the more special notion of causation as a one-sided

determination of future phenomena by means of present conditions;

it can be used to express the fact of the subsumption under a

general law of past, present, and future alike, in a sequence of

phenomena. From this point of view the remark of Huxley that

Mathematics “knows nothing of causation” could only be taken to

express the whole truth, if by the term “causation” is understood

“efficient causation.” The latter notion has, however, in recent

times been to an increasing extent regarded as just as irrelevant

in the natural sciences as it is in Mathematics; the idea of

thorough-going determinancy, in accordance with formal law, being

thought to be alone significant in either domain.--HOBSON, E. W.

_Presidential Address British

Association for the Advancement of

Science (1910); Nature, Vol. 84, p.

290._

=255.= Most, if not all, of the great ideas of modern mathematics

have had their origin in observation. Take, for instance, the

arithmetical theory of forms, of which the foundation was laid in

the diophantine theorems of Fermat, left without proof by their

author, which resisted all efforts of the myriad-minded Euler to

reduce to demonstration, and only yielded up their cause of being

when turned over in the blow-pipe flame of Gauss’s transcendent

genius; or the doctrine of double periodicity, which resulted

from the observation of Jacobi of a purely analytical fact of

transformation; or Legendre’s law of reciprocity; or Sturm’s

theorem about the roots of equations, which, as he informed me

with his own lips, stared him in the face in the midst of some

mechanical investigations connected (if my memory serves me

right) with the motion of compound pendulums; or Huyghen’s method

of continued fractions, characterized by Lagrange as one of the

principal discoveries of that great mathematician, and to which

he appears to have been led by the construction of his Planetary

Automaton; or the new algebra, speaking of which one of my

predecessors (Mr. Spottiswoode) has said, not without just reason

and authority, from this chair, “that it reaches out and

indissolubly connects itself each year with fresh branches of

mathematics, that the theory of equations has become almost new

through it, algebraic geometry transfigured in its light, that

the calculus of variations, molecular physics, and mechanics” (he

might, if speaking at the present moment, go on to add the theory

of elasticity and the development of the integral calculus) “have

all felt its influence.”--SYLVESTER, J. J.

_A Plea for the Mathematician, Nature,

Vol. 1, p. 238; Collected Mathematical

Papers, Vol. 2, pp. 655, 656._

=256.= The ability to imagine relations is one of the most

indispensable conditions of all precise thinking. No subject can

be named, in the investigation of which it is not imperatively

needed; but it can be nowhere else so thoroughly acquired as in

the study of mathematics.--FISKE, JOHN.

_Darwinism and other Essays (Boston,

1893), p. 296._

=257.= The great science [mathematics] occupies itself at least

just as much with the power of imagination as with the power of

logical conclusion.--HERBART, F. J.

_Pestalozzi’s Idee eines ABC der

Anschauung. Werke [Kehrbach]

(Langensaltza, 1890), Bd. 1, p. 174._

=258.= The moving power of mathematical invention is not

reasoning but imagination.--DE MORGAN, A.

_Quoted in Graves’ Life of Sir W. R.

Hamilton, Vol. 3 (1889), p. 219._

=259.= There is an astonishing imagination, even in the science

of mathematics.... We repeat, there was far more imagination in

the head of Archimedes than in that of Homer.--VOLTAIRE.

_A Philosophical Dictionary (Boston,

1881), Vol. 3, p. 40. Article

“Imagination.”_

=260.= As the prerogative of Natural Science is to cultivate a

taste for observation, so that of Mathematics is, almost from the

starting point, to stimulate the faculty of invention.

--SYLVESTER, J. J.

_A Plea for the Mathematician, Nature,

Vol. 1, p. 261; Collected Mathematical

Papers, Vol. 2 (Cambridge, 1908), p.

717._

=261.= A marveilous newtrality have these things mathematicall,

and also a strange participation between things supernaturall,

immortall, intellectuall, simple and indivisible, and things

naturall, mortall, sensible, componded and divisible.--DEE, JOHN.

_Euclid (1570), Preface._

=262.= Mathematics stands forth as that which unites, mediates

between Man and Nature, inner and outer world, thought and

perception, as no other subject does.--FROEBEL.

_[Herford translation] (London, 1893),

Vol. 1, p. 84._

=263.= The intrinsic character of mathematical research and

knowledge is based essentially on three properties: first, on its

conservative attitude towards the old truths and discoveries of

mathematics; secondly, on its progressive mode of development,

due to the incessant acquisition of new knowledge on the basis of

the old; and thirdly, on its self-sufficiency and its consequent

absolute independence.--SCHUBERT, H.

_Mathematical Essays and Recreations

(Chicago, 1898), p. 27._

=264.= Our science, in contrast with others, is not founded on a

single period of human history, but has accompanied the

development of culture through all its stages. Mathematics is as

much interwoven with Greek culture as with the most modern

problems in Engineering. She not only lends a hand to the

progressive natural sciences but participates at the same time in

the abstract investigations of logicians and philosophers.

--KLEIN, F.

_Klein und Riecke: Ueber angewandte

Mathematik und Physik (1900), p. 228._

=265.= There is probably no other science which presents such

different appearances to one who cultivates it and to one who

does not, as mathematics. To this person it is ancient,

venerable, and complete; a body of dry, irrefutable, unambiguous

reasoning. To the mathematician, on the other hand, his science

is yet in the purple bloom of vigorous youth, everywhere

stretching out after the “attainable but unattained” and full of

the excitement of nascent thoughts; its logic is beset with

ambiguities, and its analytic processes, like Bunyan’s road, have

a quagmire on one side and a deep ditch on the other and branch

off into innumerable by-paths that end in a wilderness.

--CHAPMAN, C. H.

_Bulletin American Mathematical Society,

Vol. 2 (First series), p. 61._

=266.= Mathematical science is in my opinion an indivisible whole,

an organism whose vitality is conditioned upon the connection of

its parts. For with all the variety of mathematical knowledge, we

are still clearly conscious of the similarity of the logical

devices, the _relationship_ of the _ideas_ in mathematics as a

whole and the numerous analogies in its different departments. We

also notice that, the farther a mathematical theory is developed,

the more harmoniously and uniformly does its construction proceed,

and unsuspected relations are disclosed between hitherto separated

branches of the science. So it happens that, with the extension of

mathematics, its organic character is not lost but manifests

itself the more clearly.--HILBERT, D.

_Mathematical Problems, Bulletin

American Mathematical Society, Vol. 8,

p. 478._

=267.= The mathematics have always been the implacable enemies of

scientific romances.--ARAGO.

_Oeuvres (1855), t. 3, p. 498._

=268.= Those skilled in mathematical analysis know that its

object is not simply to calculate numbers, but that it is also

employed to find the relations between magnitudes which cannot be

expressed in numbers and between functions whose law is not

capable of algebraic expression.--COURNOT, AUGUSTIN.

_Mathematical Theory of the Principles

of Wealth [Bacon, N. T.], (New York,

1897), p. 3._

=269.= Coterminous with space and coeval with time is the Kingdom

of Mathematics; within this range her dominion is supreme;

otherwise than according to her order nothing can exist; in

contradiction to her laws nothing takes place. On her mysterious

scroll is to be found written for those who can read it that

which has been, that which is, and that which is to come.

Everything material which is the subject of knowledge has number,

order, or position; and these are her first outlines for a sketch

of the universe. If our feeble hands cannot follow out the

details, still her part has been drawn with an unerring pen, and

her work cannot be gainsaid. So wide is the range of mathematical

sciences, so indefinitely may it extend beyond our actual powers

of manipulation that at some moments we are inclined to fall down

with even more than reverence before her majestic presence. But

so strictly limited are her promises and powers, about so much

that we might wish to know does she offer no information

whatever, that at other moments we are fain to call her results

but a vain thing, and to reject them as a stone where we had

asked for bread. If one aspect of the subject encourages our

hopes, so does the other tend to chasten our desires, and he is

perhaps the wisest, and in the long run the happiest, among his

fellows, who has learned not only this science, but also the

larger lesson which it directly teaches, namely, to temper our

aspirations to that which is possible, to moderate our desires to

that which is attainable, to restrict our hopes to that of which

accomplishment, if not immediately practicable, is at least

distinctly within the range of conception.--SPOTTISWOODE, W.

_Quoted in Sonnenschein’s Encyclopedia

of Education (London, 1906), p. 208._

=270.= But it is precisely mathematics, and the pure science

generally, from which the general educated public and independent

students have been debarred, and into which they have only rarely

attained more than a very meagre insight. The reason of this is

twofold. In the first place, the ascendant and consecutive

character of mathematical knowledge renders its results

absolutely insusceptible of presentation to persons who are

unacquainted with what has gone before, and so necessitates on

the part of its devotees a thorough and patient exploration of

the field from the very beginning, as distinguished from those

sciences which may, so to speak, be begun at the end, and which

are consequently cultivated with the greatest zeal. The second

reason is that, partly through the exigencies of academic

instruction, but mainly through the martinet traditions of

antiquity and the influence of mediæval logic-mongers, the

great bulk of the elementary text-books of mathematics have

unconsciously assumed a very repellant form,--something similar

to what is termed in the theory of protective mimicry in biology

“the terrifying form.” And it is mainly to this formidableness

and touch-me-not character of exterior, concealing withal a

harmless body, that the undue neglect of typical mathematical

studies is to be attributed.--MCCORMACK, T. J.

_Preface to De Morgan’s Elementary

Illustrations of the Differential and

Integral Calculus (Chicago, 1899)._

=271.= Mathematics in gross, it is plain, are a grievance in

natural philosophy, and with reason: for mathematical proofs,

like diamonds, are hard as well as clear, and will be touched

with nothing but strict reasoning. Mathematical proofs are out of

the reach of topical arguments; and are not to be attacked by the

equivocal use of words or declaration, that make so great a part

of other discourses,--nay, even of controversies.--LOCKE, JOHN.

_Second Reply to the Bishop of

Worcester._

=272.= The belief that mathematics, because it is abstract, because

it is static and cold and gray, is detached from life, is a mistaken

belief. Mathematics, even in its purest and most abstract estate,

is not detached from life. It is just the ideal handling of the

problems of life, as sculpture may idealize a human figure or as

poetry or painting may idealize a figure or a scene. Mathematics

is precisely the ideal handling of the problems of life, and the

central ideas of the science, the great concepts about which its

stately doctrines have been built up, are precisely the chief

ideas with which life must always deal and which, as it tumbles

and rolls about them through time and space, give it its interests

and problems, and its order and rationality. That such is the case

a few indications will suffice to show. The mathematical concepts

of constant and variable are represented familiarly in life by the

notions of fixedness and change. The concept of equation or that

of an equational system, imposing restriction upon variability,

is matched in life by the concept of natural and spiritual law,

giving order to what were else chaotic change and providing partial

freedom in lieu of none at all. What is known in mathematics under

the name of limit is everywhere present in life in the guise of

some ideal, some excellence high-dwelling among the rocks, an

“ever flying perfect” as Emerson calls it, unto which we may

approximate nearer and nearer, but which we can never quite attain,

save in aspiration. The supreme concept of functionality finds its

correlate in life in the all-pervasive sense of interdependence

and mutual determination among the elements of the world. What is

known in mathematics as transformation--that is, lawful transfer

of attention, serving to match in orderly fashion the things of

one system with those of another--is conceived in life as a

process of transmutation by which, in the flux of the world, the

content of the present has come out of the past and in its turn,

in ceasing to be, gives birth to its successor, as the boy is

father to the man and as things, in general, become what they are

not. The mathematical concept of invariance and that of infinitude,

especially the imposing doctrines that explain their meanings and

bear their names--What are they but mathematicizations of that

which has ever been the chief of life’s hopes and dreams, of that

which has ever been the object of its deepest passion and of its

dominant enterprise, I mean the finding of the worth that abides,

the finding of permanence in the midst of change, and the discovery

of a presence, in what has seemed to be a finite world, of being

that is infinite? It is needless further to multiply examples of a

correlation that is so abounding and complete as indeed to suggest

a doubt whether it be juster to view mathematics as the abstract

idealization of life than to regard life as the concrete realization

of mathematics.--KEYSER, C. J.

_The Humanization of the Teaching of

Mathematics; Science, New Series, Vol.

35, pp. 645-646._

=273.= Mathematics, like dialectics, is an organ of the inner

higher sense; in its execution it is an art like eloquence. Both

alike care nothing for the content, to both nothing is of value

but the form. It is immaterial to mathematics whether it

computes pennies or guineas, to rhetoric whether it defends truth

or error.--GOETHE.

_Wilhelm Meisters Wanderjahre, Zweites

Buch._

=274.= The genuine spirit of Mathesis is devout. No intellectual

pursuit more truly leads to profound impressions of the existence

and attributes of a Creator, and to a deep sense of our filial

relations to him, than the study of these abstract sciences. Who

can understand so well how feeble are our conceptions of Almighty

Power, as he who has calculated the attraction of the sun and the

planets, and weighed in his balance the irresistible force of the

lightning? Who can so well understand how confused is our

estimate of the Eternal Wisdom, as he who has traced out the

secret laws which guide the hosts of heaven, and combine the

atoms on earth? Who can so well understand that man is made in

the image of his Creator, as he who has sought to frame new laws

and conditions to govern imaginary worlds, and found his own

thoughts similar to those on which his Creator has acted?

--HILL, THOMAS.

_The Imagination in Mathematics; North

American Review, Vol. 85, p. 226._

=275.= ... what is physical is subject to the laws of

mathematics, and what is spiritual to the laws of God, and the

laws of mathematics are but the expression of the thoughts of

God.--HILL, THOMAS.

_The Uses of Mathesis; Bibliotheca

Sacra, Vol. 32, p. 523._

=276.= It is in the inner world of pure thought, where all

_entia_ dwell, where is every type of order and manner of

correlation and variety of relationship, it is in this infinite

ensemble of eternal verities whence, if there be one cosmos or

many of them, each derives its character and mode of being,--it

is there that the spirit of mathesis has its home and its life.

Is it a restricted home, a narrow life, static and cold and grey

with logic, without artistic interest, devoid of emotion and mood

and sentiment? That world, it is true, is not a world of _solar_

light, not clad in the colours that liven and glorify the things

of sense, but it is an illuminated world, and over it all and

everywhere throughout are hues and tints transcending _sense_,

painted there by radiant pencils of _psychic_ light, the light in

which it lies. It is a silent world, and, nevertheless, in

respect to the highest principle of art--the interpenetration of

content and form, the perfect fusion of mode and meaning--it even

surpasses music. In a sense, it is a static world, but so, too,

are the worlds of the sculptor and the architect. The figures,

however, which reason constructs and the mathematic vision

beholds, transcend the temple and the statue, alike in simplicity

and in intricacy, in delicacy and in grace, in symmetry and in

poise. Not only are this home and this life thus rich in æsthetic

interests, really controlled and sustained by motives of a

sublimed and supersensuous art, but the religious aspiration,

too, finds there, especially in the beautiful doctrine of

invariants, the most perfect symbols of what it seeks--the

changeless in the midst of change, abiding things in a world of

flux, configurations that remain the same despite the swirl and

stress of countless hosts of curious transformations. The domain

of mathematics is the sole domain of certainty. There and there

alone prevail the standards by which every hypothesis respecting

the external universe and all observation and all experiment must

be finally judged. It is the realm to which all speculation and

all thought must repair for chastening and sanitation--the court

of last resort, I say it reverently, for all intellection

whatsoever, whether of demon or man or deity. It is there that

mind as mind attains its highest estate, and the condition of

knowledge there is the ultimate object, the tantalising goal of

the aspiration, the _Anders-Streben_, of all other knowledge of

every kind.--KEYSER, C. J.

_The Universe and Beyond; Hibbert

Journal, Vol. 3 (1904-1905), pp.

313-314._

Memorabilia Mathematica; or, the Philomath's Quotation-Book · 第 1 / 17 章