"WITH THESE ELEMENTARY PRESENTATIONS THERE REMAINS ALWAYS THE DOUBT AS TO WHETHER OR NOT OUR NEGLECTING OF SUCCESSIVE SMALL QUANTITIES MAY NOT FINALLY ACCUMULATE TO A NOTICEABLE ERROR, EVEN IF EACH IS PERMISSABLE SINGLY. BUT I DO NOT NEED TO CARRY THIS OUT IN DETAIL, FOR THESE QUESTIONS ARE SO THOROUGHLY ELEMENTARY THAT EACH OF YOU CAN THINK THEM THROUGH WHEN YOU FEEL SO INCLINED."; ELEMENTARY MATHEMATICS, FROM AN ADVANCED STANDPOINT - FELIX KLEIN 1908.