# David Eugene Smith

David Eugene Smith (January 21, 1860 – July 29, 1944) was an American mathematician, educator, and editor.

## Quotes

• The field of mathematics is now so extensive that no one can [any] longer pretend to cover it, least of all the specialist in any one department. Furthermore it takes a century or more to weigh men and their discoveries, thus making the judgment of contemporaries often quite worthless.
• 1. The human mind is so constructed that it must see every perception in a time-relation—in an order—and every perception of an object in a space-relation—as outside or beside our perceiving selves.
2. These necessary time-relations are reducible to Number, and they are studied in the theory of number, arithmetic and algebra.
3. These necessary space-relations are reducible to Position and Form, and they are studied in geometry.
Mathematics, therefore, studies an aspect of all knowing, and reveals to us the universe as it presents itself, in one form, to mind. To apprehend this and to be conversant with the higher developments of mathematical reasoning, are to have at hand the means of vitalizing all teaching of elementary mathematics.

### History of Mathematics (1923) Vol.1

David Eugene Smith. History of Mathematics (1923) Vol.1

• The fact that arithmetic and geometry took such a notable step forward... was due in no small measure to the introduction of Egyptian papyrus into Greece. This event occurred about 650 B.C., and the invention of printing in the 15th century did not more surely effect a revolution in thought than did this introduction of writing material on the northern shores of the Mediterranean Sea just before the time of Thales.
• The excellent work of Tropfke is an example of the tendency to break away from the mere chronological recital of facts.
• More than any of his predecessors Plato appreciated the scientific possibilities of geometry. .. By his teaching he laid the foundations of the science, insisting upon accurate definitions, clear assumptions, and logical proof. His opposition to the materialists, who saw in geometry only what was immediately useful to the artisan and the mechanic is... clear. ...That Plato should hold the view... is not a cause for surprise. The world's thinkers have always held it. No man has ever created a mathematical theory for practical purposes alone. The applications of mathematics have generally been an afterthought.
• p. 90
• Grégoire de Saint-Vincent... was a Jesuit, taught mathematics in Rome and Prag (1629-1631), and was afterwards called to Spain by Phillip IV as tutor to his son... He wrote two works on geometry [Principia Matheseos Univerales (1651); Exercitationum Mathematicarum Libri quinque (1657)], giving in one of them the quadrature of the hyperbola referred to its asymptotes, and showing that as the area increased in arithmetic series the abscissas increased in geometric series.
• Of the contemporaries of Newton one of the most prominent was John Wallis. ...Wallis was a voluminous writer, and not only are his writings erudite, but they show a genius in mathematics... He was one of the first to recognize the significance of the generalization of exponents to include negative and fractional as well as positive and integral numbers. He recognized also the importance of Cavalieri's method of indivisibles, and employed it in the quadrature of such curves as y=xn, y=x1/n, and y=x0 + x1 + x2 +... He failed in his attempts at the approximate quadrature of the circle by means of series because he was not in possession of the general form of the binomial theorem. He reached the result, however, by another method. He also obtained the equivalent of ${\displaystyle ds=\!dx{\sqrt {1+({\frac {dy}{dx}})^{2}}}}$ for the length of an element of a curve, thus connecting the problem of rectification with that of quadrature.
• In 1673 he wrote his great work De Algebra Tractatus; Historicus & Practicus, of which an English edition appeared in 1685. In this there is seen the first serious attempt in England to write on the history of mathematics, and the result shows a wide range of reading of classical literature of the science. This work is also noteworthy because it contains the first of an effort to represent the imaginary number graphically by the method now used. The effort stopped short of success but was an ingenious beginning.
• Wallis was in sympathy with Greek mathematics and astronomy, editing parts of the works of Archimedes, Eutocius, Ptolemy, and Aristarchus; but at the same time he recognized the fact that the analytic method was to replace the synthetic, as when he defined a conic as a curve of the second degree instead of as a section of a cone, and treated it by the aid of coordinates.
• His writings include works on mechanics, sound, astronomy, the tides, the laws of motion, the Torricellian tube, botany, physiology, music, the calendar (in opposition to the Gregorian reform), geology, and the compass,—a range too wide to allow of the greatest success in any of the lines of his activity. He was also an ingenious cryptologist and assisted the government in deciphering diplomatic messages.
• Among his [John Wallis'] interesting discoveries was the relation
${\displaystyle {\frac {4}{\pi }}={\frac {3}{2}}\cdot {\frac {3}{4}}\cdot {\frac {5}{4}}\cdot {\frac {5}{6}}\cdot {\frac {7}{6}}\cdot {\frac {7}{8}}\cdots }$
one of the early values of π involving infinite products.
• p. 441 Footnote: see his Opera Mathematica, I

### History of Mathematics (1925) Vol.2

David Eugene Smith, History of Mathematics (1925), Vol.2

• The Arabs contributed nothing new to the theory, but al-Khowârizmî (c. 825) states the usual rules, and the same is true of his successors.
• When we speak of the early history of algebra it is necessary to consider... the meaning of the term. If... we mean the science that allows us to solve the equation ${\displaystyle ax^{2}+bx+c=0}$, expressed in these symbols, then the history begins in the 17th century; if we remove the restriction as to these particular signs, and allow for other and less convenient symbols, we might properly begin the history in the 3rd century; if we allow for the solution of the above equation by geometric methods, without algebraic symbols of any kind, we might say that algebra begins with the Alexandrian School or a little earlier; and if we say that we should class as algebra any problem that we should now solve with algebra (even though it was as first solved by mere guessing or by some cumbersome arithmetic process), the the science was known about 1800 B.C., and probably still earlier.<
• Ch. 6: Algebra, p. 378
• The first writer on algebra whose works have come down to us is Ahmes. He has certain problems in linear equations and in series, and these form the essentially new feature in his work. His treatment of the subject is largely rhetorical.
• Ch. 6: Algebra
• There are only four Hindu writers on algebra whose names are particularly noteworthy. These are Āryabhata, whose Āryabhatiyam (c. 510) included problems in series, permutations, and linear and quadratic equations; Brahmagupta, whose Brahmasiddhānta (c. 628) contains a satisfactory rule for solving the quadratic... Mahāvīra, whose Ganita-Sāra Sangraha (c. 850) contains a large number of problems involving series, radicals, and equations; and Bhāskara, whose Bija Ganita (c. 1150)... extends the work through quadratic equations.
• Ch. 6: Algebra
• It is difficult to say when algebra as a science began in China. Problems which we should solve by equations appear in works as early as the Nine Sections (K'iu-ch'ang Suan-shu) and so may have been known by the year 1000 B.C. In Liu Hui's commentary on this work (c. 250) there are problems of pursuit, the Rule of False Position... and an arrangement of terms in a kind of determinant notation. The rules given by Liu Hui form a kind of rhetorical algebra.
The work of Sun-tzï contains various problems which would today be considered algebraic. These include questions involving indeterminate equations. ...Sun-tzï solved such problems by analysis and was content with a single result...
The Chinese certainly knew how to solve quadratics as early as the 1st century B.C., and rules given even as early as the K'iu-ch'ang Suan-shu... involve the solution of such equations.
Liu Hui (c. 250) gave various rules which would now be stated as algebraic formulas and seems to have deduced these from other rules in much the same way as we should...
By the 7th century the cubic equation had begun to attract attention, as is evident from the Ch'i-ku Suan-king of Wang Hs'iao-t'ung (c. 625).
The culmination of Chinese is found in the 13th century. ...numerical higher equations attracted the special attention of scholars like Ch'in Kiu-shao (c.1250), Li Yeh (c. 1250), and Chu-Shï-kié (c. 1300), the result being the perfecting of an ancient method which resembles the one later developed by W. G. Horner (1819).
• Ch. 6: Algebra
• With the coming of the Jesuits in the 16th century, and the consequent introduction of Western science, China lost interest in her native algebra...
• Ch. 6: Algebra
• Algebra in the Renaissance period received its first serious consideration in Pacioli's Sūma (1494)... which characterized in a careless way the knowledge... thus far accumulated. By the aid of the crude symbolism then in use it gave a considerable amount of work in equations.
The noteworthy work... and the first to be devoted entirely to the subject, was Rudolff's Coss (1525). This work made no decided advance in the theory, but it improved the symbolism for radicals and made the science better known in Germany. Stiffel's edition of this work (1553-1554) gave the subject still more prominence.
The first epoch-making algebra to appear in print was the Ars Magna of Cardan (1545). The next great work... to appear in print was the General Trattato of Tartaglia...
• p. 384; Ch. 6: Algebra
• The first epoch-making algebra to appear in print was the Ars Magna of Cardan (1545). This was devoted primarily to the solution of algebraic equations. It contained the solution of the cubic and biquadratic equations, made use of complex numbers, and in general may be said to have been the first step toward modern algebra.
• p.384
• The first noteworthy attempt to write an algebra in England was made by Robert Recorde, whose Whetstone of witte (1557) was an excellent textbook for its time. The next important contribution was Masterson's incomplete treatise of 1592-1595, but the work was not up to the standard set by Recorde.
The first Italian textbook to bear the title of algebra was Bombelli's work of 1572.
By this time elementary algebra was fairly well perfected, and it only remained to develop a good symbolism. ...this was worked out largely by Vieta (c. 1590), Harriot (c. 1610), Oughtred (c. 1628), Descartes (1637), and the British school of Newton's time (c. 1675).
So far as the great body of elementary algebra is concerned, therefore, it was completed in the 17th century.
• p. 386, Ch. 6: Algebra,-->
• Vieta (c. 1590) rejected the name "algebra" as having no significance in the European languages, and proposed to use the word "analysis," and it is probably to his influence that the popularity of this term in connection with higher algebra is due.
• p. 392
• Vieta: 1QC - 15QQ + 85C - 225Q + 274N, aequator 120. Modern form:
${\displaystyle x^{6}-15x^{4}+85x^{3}-225x^{2}+274x=120}$
• p.430
• He used capital vowels for the unknown quantities and capital consonants for the known, thus being able to express several unknowns and several knowns.
• p. 430; footnote
• In the work of Vieta the analytic methods replaced the geometric, and his solutions of the quadratic equation were therefore a distinct advance upon those of his predecessors. For example, to solve the equation ${\displaystyle x^{2}+ax+b=0}$ he placed ${\displaystyle u+z}$ for ${\displaystyle x}$. He then had
${\displaystyle u^{2}+(2z+a)u+(z^{2}+az+b)=0.}$
He now let ${\displaystyle 2z+a=0,}$ whence ${\displaystyle z=-{\frac {1}{2}}a,}$and this gave
${\displaystyle u^{2}-{\frac {1}{4}}(a^{2}-4b)=0.}$
${\displaystyle u=\pm {\frac {1}{2}}{\sqrt {a^{2}-4b}}.}$
and
${\displaystyle x=u+z=-{\frac {1}{2}}a\pm {\sqrt {a^{2}-4b}}.}$
• p.449
• [Zuanne de Tonini] da Coi... impuned Tartaglia to publish his method, but the latter declined to do so. In 1539 Cardan wrote to Tartaglia, and a meeting was arranged at which, Tartaglia says, having pledged Cardan to secrecy, he revealed the method in cryptic verse and later with a full explanation. Cardan admits that he received the solution from Tartaglia, but... without any explanation. At any rate, the two cubics ${\displaystyle x^{3}+ax^{2}=c}$ and ${\displaystyle x^{3}+bx=c}$ could now be solved. The reduction of the general cubic ${\displaystyle x^{3}+ax^{2}+bx=c}$ to the second of these forms does not seem to have been considered by Tartaglia at the time of the controversy. When Cardan published his Ars Magna however, he transformed the types ${\displaystyle x^{3}=ax^{2}+c}$ and ${\displaystyle x^{3}+ax^{2}=c}$ by substituting ${\displaystyle x=y+{\frac {1}{3}}a}$ and ${\displaystyle x=y-{\frac {1}{3}}a}$ respectively, and transformed the type ${\displaystyle x^{3}+c=ax^{2}}$ by the substitution ${\displaystyle x={\sqrt[{3}]{c^{2}/y}},}$ thus freeing the equations of the term ${\displaystyle x^{2}}$. This completed the general solution, and he applied the method to the complete cubic in his later problems.
• p.461
• Cardan's originality in the matter seems to have been shown chiefly in four respects. First, he reduced the general equation to the type ${\displaystyle x^{3}+bx=c}$; second, in a letter written August 4, 1539, he discussed the question of the irreducible case; third, he had the idea of the number of roots to be expected in the cubic; and, fourth, he made a beginning in the theory of symmetric functions. ...With respect to the irreducible case... we have the cube root of a complex number, thus reaching an expression that is irreducible even though all three values of x turn out to be real. With respect to the number of roots to be expected in the cubic... before this time only two roots were ever found, negative roots being rejected. As to the question of symmetric functions, he stated that the sum of the roots is minus the coefficient of x2
• pp.461-464
• He states that the root of ${\displaystyle x^{3}+6x=20}$ is
${\displaystyle x={\sqrt[{3}]{{\sqrt {108}}+10}}-{\sqrt[{3}]{{\sqrt {108}}-10}}.}$
• p.464
• He... gave thirteen forms of the cubic which have positive roots, these having already been given by Omar Kayyam.
• p.464
• Although Cardan reduced his particular equations to forms lacking a term in ${\displaystyle x^{2}}$, it was Vieta who began with the general form
${\displaystyle x^{3}+px^{2}+qx+r=0}$
and made the substitution ${\displaystyle x=y-{\frac {1}{3}}p,}$ thus reducing the equation to the form
${\displaystyle y^{3}+3by=2c.}$
He then made the substitution
${\displaystyle z^{3}+yz=b,}$   or   ${\displaystyle y={\frac {b-z^{2}}{z}},}$
which led to the form
${\displaystyle z^{6}+2cz^{2}=b^{2},}$
a sextic which he solved as a quadratic.
• p.465
• The problem of the biquadratic equation was laid prominently before Italian mathematicians by Zuanne de Tonini da Coi, who in 1540 proposed the problem, "Divide 10 parts into three parts such that they shall be continued in proportion and that the product of the first two shall be 6." He gave this to Cardan with the statement that it could not be solved, but Cardan denied the assertion, although himself unable to solve it. He gave it to Ferrari, his pupil, and the latter, although then a mere youth, succeeded where the master had failed. ...This method soon became known to algebraists through Cardan's Ars Magna, and in 1567 we find it used by Nicolas Petri [of Deventer].
• pp.467-468
• The law which asserts that the equation X = 0, complete or incomplete, can have no more real positive roots than it has changes of sign, and no more real negative roots than it has permanences of sign, was apparently known to Cardan; but a satisfactory statement is possibly due to Harriot (died 1621) and certainly to Descartes.
• p.469
• Vieta was the first algebraist after Ferrari to make any noteworthy advance in the solution of the biquadratic. He began with the type ${\displaystyle x^{4}+2gx^{2}+bx=c,}$ wrote it as ${\displaystyle x^{4}+2gx^{2}=c-bx,}$ added ${\displaystyle gx^{2}+{\frac {1}{4}}y^{2}+yx^{2}+gy}$ to both sides, and then made the right side a square after the manner of Ferrari. This method... requires the solution of a cubic resolvent.
Descartes (1637) next took up the question and succeeded in effecting a simple solution... a method considerably improved (1649) by his commentator Van Schooten. The method was brought to its final form by Simpson (1745).
• p.469
• It is difficult to say who it is who first recognized the advantage of always equating to zero in the study of the general equation. It may very likely have been Napier, for he wrote his De Arte Logistica before 1594, and in this there is evidence that he understood the advantage of this procedure. Bürgi also recognized the value of making the second member zero, Harriot may have done the same, and the influence of Descartes was such that the usage became fairly general.
• Aside from Cauchy, the greatest contributory to the theory [of determinants] was Carl Gustav Jacob Jacobi. With him the word "determinant" received its final acceptance. He early used the functional determinant which Sylvester has called the Jacobian, and in his famous memoirs in Crelle's Journal for 1841 he considered these forms as well as that class of alternating functions which Sylvester has called alternants.

## Quotes about David Eugene Smith

• Johannes Tropfke... described the history of those individual parts of mathematics that he believed were most important for mathematics as taught in secondary schools. He intended his history to inform teachers about the origin of special problems, terms, and methods in school mathematics. ...Tropfke's approach to the history of mathematics at this time was new and even now is not yet out of date. The only comparable work is the second volume of D.E Smith's History of Mathematics... which gives far less detailed information.
• Menso Folkerts, Cristoph J. Scriba, Hans Wussing, "Germany", Writing the History of Mathematics - Its Historical Development (2002).