"A mathematician is not a man who can readily manipulate figures; often he cannot. He is not even a man who can readily perform the transformation of equations by the use of calculus. He is primarily an individual who is skilled in the use of symbolic logic on a high plane, and especially he is a man of intuitive judgment in the choice of the manipulative processes he employs." -- Vannevar Bush, inventor and politician (b. 1890-03-11, d. 1974-06-30), "As We May Think", Atlantic Monthly, July 1945
[Speaking of mathematicians, Descarte's birthday is today and Laplace's birthday was Friday.]