Quotes from William Dunham

That this blind and aging man forged ahead with such gusto is a remarkable lesson, a tale for the ages. Euler's courage, determination, and utter unwillingness to be beaten serves, in the truest sense of the word, as an inspiration for mathematician and non-mathematician alike. The long history of mathematics provides no finer example of the triumph of the human spirit.

Never was his remarkable memory more useful than when he could see mathematics only in his mind's eye.

In his eulogy, the Marquis de Condorcet observed that whosoever pursues mathematics in the future will be guided and sustained by the genius of Euler and asserted , with much justification, that all mathematicians...are his disciples.

To this day the existence of odd perfect numbers remains unsolved.

I have assuredly found an admirable proof of this, but the margin is too narrow to contain it.