Rock singers often say that it was their adversity that drove them to create their classics, such as heartache, sorrow, or losing something in their lives. And, so, we might quote:

Sweet are the uses of adversity — William Shakespeare

One such person who had considerable adversity is Leonhard Euler and who lived from 1707 to 1783. Leonhard was truly one of the greatest minds who has ever graced this planet:

“Read Euler, read Euler, he is the master of us all” — Pierre-Simon Laplace

But, he suffered great adversity in his life and eventually went blind. His blindness, though, seemed to just increase his outputs — as it allowed him to focus his mind on core problems. In fact, in 1775 — four years after he had gone blind — he proposed a mathematical paper every week. On going blind, he was quoted:

“Now I will have fewer distractions.”

Leonhard output of truly original thought in his time of adversity has possibly never been equalled by any mortal soul. And, his legacy lives on and is part of virtually every single transaction on the Internet. In fact, his maths has made our digital world so much safer.

The fundamentals

This article could in no way define all of Leonhard’s contributions, but one of the most fundamental is that he took the basics of integral calculus — as sketchily defined by Newton and Leibniz — and perfected it. In our modern world, so many things in our lives depend on calculus for their solutions, such as where we see changes in the physical parameters in our world. Calculus, for example, links the distances we travel over time to speed, and then changes in our speed to acceleration and deceleration. Overall, it basically makes sense of the dynamics of our world — an ever-changing and sometimes chaotic world.

Further reading here.