The greatest mathematician that never lived - Pratik Aghor

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When Nicolas Bourbaki applied to the American Mathematical Society in the 1950s, he was already one of the most influential mathematicians of his time. He'd published articles in international journals and his textbooks were required reading. Yet his application was firmly rejected for one simple reason: Nicolas Bourbaki did not exist. How is that possible? Pratik Aghor digs into the mystery.

Lesson by Pratik Aghor, directed by Província Studio.

When Nicolas Bourbaki applied
to the American Mathematical Society

in the 1950s,

he was already one of the most influential
mathematicians of his time.

He’d published articles
in international journals

and his textbooks were required reading.

Yet his application was firmly rejected
for one simple reason—

Nicolas Bourbaki did not exist.

Two decades earlier,
mathematics was in disarray.

Many established mathematicians had lost
their lives in the first World War,

and the field had become fragmented.

Different branches used disparate
methodology to pursue their own goals.

And the lack of a shared
mathematical language

made it difficult to share
or expand their work.

In 1934, a group of French mathematicians
were particularly fed up.

While studying at the prestigious
École normale supérieure,

they found the textbook
for their calculus class so disjointed

that they decided to write a better one.

The small group
quickly took on new members,

and as the project grew,
so did their ambition.

The result was
the "Éléments de mathématique,"

a treatise that sought to create
a consistent logical framework

unifying every branch of mathematics.

The text began
with a set of simple axioms—

laws and assumptions it would use
to build its argument.

From there, its authors derived
more and more complex theorems

that corresponded with work
being done across the field.

But to truly reveal common ground,

the group needed to identify
consistent rules

that applied to a wide range of problems.

To accomplish this, they gave new,
clear definitions

to some of the most important
mathematical objects,

including the function.

It’s reasonable to think of functions
as machines

that accept inputs and produce an output.

But if we think of functions
as bridges between two groups,

we can start to make claims about
the logical relationships between them.

For example, consider a group of numbers
and a group of letters.

We could define a function where
every numerical input corresponds

to the same alphabetical output,

but this doesn’t establish
a particularly interesting relationship.

Alternatively, we could define a function
where every numerical input

corresponds to a different
alphabetical output.

This second function sets up
a logical relationship

where performing a process on the input
has corresponding effects

on its mapped output.

The group began to define functions by how
they mapped elements across domains.

If a function’s output came
from a unique input,

they defined it as injective.

If every output can be mapped
onto at least one input,

the function was surjective.

And in bijective functions, each element
had perfect one to one correspondence.

This allowed mathematicians to establish
logic that could be translated

across the function’s domains
in both directions.

Their systematic approach
to abstract principles

was in stark contrast to the popular
belief that math was an intuitive science,

and an over-dependence on logic
constrained creativity.

But this rebellious band of scholars
gleefully ignored conventional wisdom.

They were revolutionizing the field,
and they wanted to mark the occasion

with their biggest stunt yet.

They decided to publish
"Éléments de mathématique"

and all their subsequent work
under a collective pseudonym:

Nicolas Bourbaki.

Over the next two decades, Bourbaki’s
publications became standard references.

And the group’s members took their prank
as seriously as their work.

Their invented mathematician claimed
to be a reclusive Russian genius

who would only meet
with his selected collaborators.

They sent telegrams in Bourbaki’s name,
announced his daughter’s wedding,

and publicly insulted anyone
who doubted his existence.

In 1968, when they could
no longer maintain the ruse,

the group ended their joke
the only way they could.

They printed Bourbaki’s obituary,
complete with mathematical puns.

Despite his apparent death, the group
bearing Bourbaki’s name lives on today.

Though he’s not associated
with any single major discovery,

Bourbaki’s influence informs
much current research.

And the modern emphasis on formal proofs
owes a great deal to his rigorous methods.

Nicolas Bourbaki may have been imaginary—
but his legacy is very real.