Euler was a voluminous writer on mathematics, indeed, the most
prolific writer in the history of the subject. His name is
attached to every branch of the study. It is of interest to note
that his amazing productivity was not in the least impaired
when, about 1766, he had the misfortune to become totally blind.
In addition to being a great research writer for some of the
journals of his time, Euler was also a masterful writer of
textbooks, in which he presented his material with great
clarity, detail, and completeness. These texts enjoyed a marked
and a long popularity, and to this day make very interesting and
profitable reading. One cannot but be surprised at Euler's
enormous fertility of ideas, and it is no wonder that so many of
the great mathematicians coming after him have admitted their
indebtedness to him. Euler was helped and encouraged by his
father in the choice of mathematics as a vocation. His father
was a Calvinist pastor with an interest in mathematics, having
studied the subject under Jakob Ber