While Dyson’s birds and frogs archetypes of mathematicians is oft-mentioned, David Mumford’s tribes of mathematicians is underappreciated, and I find myself pointing to it often in discussions that devolve into “my preferred kind of math research is better than yours”-type aesthetic arguments:
… the subjective nature and attendant excitement during mathematical activity, including a sense of its beauty, varies greatly from mathematician to mathematician… I think one can make a case for dividing mathematicians into several tribes depending on what most strongly drives them into their esoteric world. I like to call these tribes explorers, alchemists, wrestlers and detectives. Of course, many mathematicians move between tribes and some results are not cleanly part the property of one tribe.
Explorers are people who ask—are there objects with such and such properties and if so, how many? They feel they are discovering what lies in some distant mathematical continent and, by dint of pure thought, shining a light and reporting back what lies out there. The most beautiful things for them are the wholly new objects that they discover (the phrase ‘bright shiny objects’ has been in vogue recently) and these are especially sought by a sub-tribe that I call Gem Collectors. Explorers have another sub-tribe that I call Mappers who want to describe these new continents by making some sort of map as opposed to a simple list of ‘sehenswürdigkeiten’.
Alchemists, on the other hand, are those whose greatest excitement comes from finding connections between two areas of math that no one had previously seen as having anything to do with each other. This is like pouring the contents of one flask into another and—something amazing occurs, like an explosion!
Wrestlers are those who are focussed on relative sizes and strengths of this or that object. They thrive not on equalities between numbers but on inequalities, what quantity can be estimated or bounded by what other quantity, and on asymptotic estimates of size or rate of growth. This tribe consists chiefly of analysts and integrals that measure the size of functions but people in every field get drawn in.
Finally Detectives are those who doggedly pursue the most difficult, deep questions, seeking clues here and there, sure there is a trail somewhere, often searching for years or decades. These too have a sub-tribe that I call Strip Miners: these mathematicians are convinced that underneath the visible superficial layer, there is a whole hidden layer and that the superficial layer must be stripped off to solve the problem. The hidden layer is typically more abstract, not unlike the ‘deep structure’ pursued by syntactical linguists. Another sub-tribe are the Baptizers, people who name something new, making explicit a key object that has often been implicit earlier but whose significance is clearly seen only when it is formally defined and given a name.
Mumford’s examples of each, both results and mathematicians:
Explorers:
Theaetetus (ncient Greek list of the five Platonic solids)
Ludwig Schläfli (extended the Greek list to regular polytopes in n dimensions)
Bill Thurston (“I never met anyone with anything close to his skill in visualization”)
the list of finite simple groups
Michael Artin (discovered non-commutative rings “lying in the middle ground between the almost commutative area and the truly huge free rings”)
Set theorists (“exploring that most peculiar, almost theological world of ‘higher infinities’”)
Mappers:
Mumford himself
arguably, the earliest mathematicians (the story told by cuneiform surveying tablets)
the Mandelbrot set
Ramanujan’s “integer expressible two ways as a sum of two cubes”
Oscar Zariski, Mumford’s PhD advisor (“his deepest work was showing how the tools of commutative algebra, that had been developed by straight algebraists, had major geometric meaning and could be used to solve some of the most vexing issues of the Italian school of algebraic geometry”)
the Riemann-Roch theorem (“it was from the beginning a link between complex analysis and the geometry of algebraic curves. It was extended by pure algebra to characteristic p, then generalized to higher dimensions by Fritz Hirzebruch using the latest tools of algebraic topology. Then Michael Atiyah and Isadore Singer linked it to general systems of elliptic partial differential equations, thus connecting analysis, topology and geometry at one fell swoop”)
Wrestlers:
Archimedes (“he loved estimating π and concocting gigantic numbers”)
Calculus (“stems from the work of Newton and Leibniz and in Leibniz’s approach depends on distinguishing the size of infinitesimals from the size of their squares which are infinitely smaller”)
Euler’s strange infinite series formulas
Stirling’s formula for the approximate size of n!
Augustin-Louis Cauchy (“his eponymous inequality remains the single most important inequality in math”)
Sergei Sobolev
Shing-Tung Yau
Detectives:
Andrew Wiles is probably the archetypal example
Roger Penrose (“”My own way of thinking is to ponder long and, I hope, deeply on problems and for a long time … and I never really let them go.”)
Strip Miners:
Alexander Grothendieck (“he greatest contemporary practitioner of this philosophy in the 20th century… Of all the mathematicians that I have met, he was the one whom I would unreservedly call a “genius”. … He considered that the real work in solving a mathematical problem was to find le niveau juste in which one finds the right statement of the problem at its proper level of generality. And indeed, his radical abstractions of schemes, functors, K-groups, etc. proved their worth by solving a raft of old problems and transforming the whole face of algebraic geometry)
Leonard Euler from Switzerland and Carl Fredrich Gauss (“both showed how two dimensional geometry lay behind the algebra of complex numbers”)
Eudoxus and his spiritual successor Archimedes (“he level they reached was essentially that of a rigorous theory of real numbers with which they are able to calculate many specific integrals. Book V in Euclid’s Elements and Archimedes The Method of Mechanical Theorems testify to how deeply they dug”)
Aryabhata
Some miscellaneous humorous quotes:
When I was teaching algebraic geometry at Harvard, we used to think of the NYU Courant Institute analysts as the macho guys on the scene, all wrestlers. I have heard that conversely they used the phrase ‘French pastry’ to describe the abstract approach that had leapt the Atlantic from Paris to Harvard.
Besides the Courant crowd, Shing-Tung Yau is the most amazing wrestler I have talked to. At one time, he showed me a quick derivation of inequalities I had sweated blood over and has told me that mastering this skill was one of the big steps in his graduate education. Its crucial to realize that outside pure math, inequalities are central in economics, computer science, statistics, game theory, and operations research. Perhaps the obsession with equalities is an aberration unique to pure math while most of the real world runs on inequalities.
In many ways [the Detective approach to mathematical research exemplified by e.g. Andrew Wiles] is the public’s standard idea of what a mathematician does: seek clues, pursue a trail, often hitting dead ends, all in pursuit of a proof of the big theorem. But I think it’s more correct to say this is one way of doing math, one style. Many are leery of getting trapped in a quest that they may never fulfill.
While Dyson’s birds and frogs archetypes of mathematicians is oft-mentioned, David Mumford’s tribes of mathematicians is underappreciated, and I find myself pointing to it often in discussions that devolve into “my preferred kind of math research is better than yours”-type aesthetic arguments:
Mumford’s examples of each, both results and mathematicians:
Explorers:
Theaetetus (ncient Greek list of the five Platonic solids)
Ludwig Schläfli (extended the Greek list to regular polytopes in n dimensions)
Bill Thurston (“I never met anyone with anything close to his skill in visualization”)
the list of finite simple groups
Michael Artin (discovered non-commutative rings “lying in the middle ground between the almost commutative area and the truly huge free rings”)
Set theorists (“exploring that most peculiar, almost theological world of ‘higher infinities’”)
Mappers:
Mumford himself
arguably, the earliest mathematicians (the story told by cuneiform surveying tablets)
the Mandelbrot set
Ramanujan’s “integer expressible two ways as a sum of two cubes”
the Concinnitas project of Bob Feldman and Dan Rockmore of ten aquatints
Alchemists:
Abraham De Moivre
Oscar Zariski, Mumford’s PhD advisor (“his deepest work was showing how the tools of commutative algebra, that had been developed by straight algebraists, had major geometric meaning and could be used to solve some of the most vexing issues of the Italian school of algebraic geometry”)
the Riemann-Roch theorem (“it was from the beginning a link between complex analysis and the geometry of algebraic curves. It was extended by pure algebra to characteristic p, then generalized to higher dimensions by Fritz Hirzebruch using the latest tools of algebraic topology. Then Michael Atiyah and Isadore Singer linked it to general systems of elliptic partial differential equations, thus connecting analysis, topology and geometry at one fell swoop”)
Wrestlers:
Archimedes (“he loved estimating π and concocting gigantic numbers”)
Calculus (“stems from the work of Newton and Leibniz and in Leibniz’s approach depends on distinguishing the size of infinitesimals from the size of their squares which are infinitely smaller”)
Euler’s strange infinite series formulas
Stirling’s formula for the approximate size of n!
Augustin-Louis Cauchy (“his eponymous inequality remains the single most important inequality in math”)
Sergei Sobolev
Shing-Tung Yau
Detectives:
Andrew Wiles is probably the archetypal example
Roger Penrose (“”My own way of thinking is to ponder long and, I hope, deeply on problems and for a long time … and I never really let them go.”)
Strip Miners:
Alexander Grothendieck (“he greatest contemporary practitioner of this philosophy in the 20th century… Of all the mathematicians that I have met, he was the one whom I would unreservedly call a “genius”. … He considered that the real work in solving a mathematical problem was to find le niveau juste in which one finds the right statement of the problem at its proper level of generality. And indeed, his radical abstractions of schemes, functors, K-groups, etc. proved their worth by solving a raft of old problems and transforming the whole face of algebraic geometry)
Leonard Euler from Switzerland and Carl Fredrich Gauss (“both showed how two dimensional geometry lay behind the algebra of complex numbers”)
Eudoxus and his spiritual successor Archimedes (“he level they reached was essentially that of a rigorous theory of real numbers with which they are able to calculate many specific integrals. Book V in Euclid’s Elements and Archimedes The Method of Mechanical Theorems testify to how deeply they dug”)
Aryabhata
Some miscellaneous humorous quotes: