Introduction (From Wikipedia):
Leonhard Euler 15 April 1707 – 18 September 1783) was a Swiss mathematician, physicist, astronomer, logician and engineer who made important and influential discoveries in many branches of mathematics, such as infinitesimal calculus and graph theory, while also making pioneering contributions to several branches such as topology and analytic number theory. He also introduced much of the modern mathematical terminology and notation, particularly for mathematical analysis, such as the notion of a mathematical function.[3] He is also known for his work in mechanics, fluid dynamics, optics, astronomy and music theory.[4]
Euler was one of the most eminent mathematicians of the 18th century and is held to be one of the greatest in history. He is also widely considered to be the most prolific mathematician of all time. His collected works fill 60 to 80 quarto volumes,[5] more than anybody in the field. He spent most of his adult life in Saint Petersburg, Russia, and in Berlin, then the capital of Prussia.
A statement attributed to Pierre-Simon Laplace expresses Euler’s influence on mathematics: “Read Euler, read Euler, he is the master of us all.”[6][7]
Acts of Providence:
There are numerous providential occurrences in regard to the circumstances of the upbringing of Euler and natural talents that he had as well as developments in his life that led to him being the most prolific mathematician of all time and one of the greatest:
1)The university of Basil where he enrolled providentially boasted the greatest living mathematician at its head- Johann Bernoulli (1667-1748)- even though it was otherwise a relatively unimportant one. Interestingly, his father providentially “happened” to be friendly with the Bernoulli family. Johann became his mentor and this is one of the main contributions of Johann’s legacy!
This is how Euler himself described it:
“In 1720 I was admitted to the university… where I soon found the opportunity to become acquainted with the famous professor Johann Bernoulli, who made it a special pleasure for himself to help me along in the mathematical sciences. Private lessons, however, he categorically ruled out because of his busy schedule. However, he gave me a far more beneficial advice, which consisted in myself getting a hold of some of the more difficult mathematical books and working through them with great diligence (note: this was a trait Euler had throughout his life – to always work with great diligence up to and including the day he died) and should I encounter some objections or difficulties, he offered me free access to him every Saturday afternoon, and he was gracious enough to comment on the collected difficulties, which was done with such a desired advantage that, when he resolved one of my objections, ten others at once disappeared, which certainly is the best method of making happy progress in the mathematical sciences.”
(https://www.cs.purdue.edu/homes/wxg/EulerLect.pdf)
2)Becoming blind actually increased his productivity to the point where he produced the most material of any mathematician in history.
Euler remarked on his loss of vision, “Now I will have fewer distractions.”[24] However, his condition appeared to have little effect on his productivity…With the aid of his scribes, Euler’s productivity on many areas of study actually increased. He produced, on average, one mathematical paper every week in the year 1775.[5] (Wikipedia)
3)An exceptional memory and exceptional mental calculating abilities. “Euler could repeat the Aeneid of Virgil from beginning to end without hesitation, and for every page in the edition he could indicate which line was the first and which the last.” (Wikipedia) This allowed him to retain all the information he needed to continue his astonishing production at such a pace that there was a sixty year backlog after his death where the University kept publishing his writings.
4) The fact that he was denied the professorship at the University of Basel. Because of this, he eventually obtained a position at the Russian Academy of Science where he remained for most of his life and where his production in the last period of his life was astonishing. “Johann Bernoulli’s two sons, Daniel and Nicolaus, were working at the Imperial Russian Academy of Sciences in Saint Petersburg. On 31 July 1726, Nicolaus died of appendicitis after spending less than a year in Russia.[12][13] When Daniel assumed his brother’s position in the mathematics/physics division, he recommended that the post in physiology that he had vacated be filled by his friend Euler. In November 1726 Euler eagerly accepted the offer, but delayed making the trip to Saint Petersburg while he unsuccessfully applied for a physics professorship at the University of Basel.”[14] (Wikipedia)
5) The fact that his father was a theologian and he had a religious upbringing. This led him to conduct a generally righteous lifestyle and removed the distractions that frivolity brings. Additionally, it was one of the reasons for his leaving Berlin: “He felt increasingly uncomfortable and frustrated in the company of so many “free-spirits”—as he and others called the followers of French enlightenment—that populated and began to dominate the Berlin Academy…It may also have been one, and not the least, of the reasons why Euler left Berlin and returned to St. Petersburg.” (https://www.cs.purdue.edu/homes/wxg/EulerLect.pdf)
