German mathematician Georg Cantor is born in St. Petersburg, Russia. Georg Cantor will create set theory which has become fundamental to modern mathematics.

Cantor also discovered some of the first paradoxes in set theory. One, often called "Cantor's paradox," is that every set actually has **more** subsets than it does **members**. The consequence of this is theat there can be no "set of all sets."

As Georg Cantor says:

"In mathematics the art of proposing a question must be held of higher value than solving it."