The calculus is the greatest aid we have to the appreciation of physical
truth in the broadest sense of the word.
W.F. Osgood, quoted in Bulletin American Mathematical Society, Vol.13 (1907).
The calculus is one of the grandest edifices constructed by mankind.
Cambridge Conference on School Mathematics, quoted in Out of the Mouths of Mathematicians, R. Schmalz.
Found at Mathematics and Education Quotation Server Homepage