The Greatness of Louise de Marillac can never be understood until this false image of a timid, drab, and cheerless woman has been put aside. In undertaking this biography, my aim was to exorcise this disagreeable mythical creature and call up real Louise. I went, therefore, to her letters and writings. No one, however he might try, can hide behind the pen. No one can help but reveal himself-personality, character, and qualities, good and bad-in letters, which are products of the most unguarded moments of life. And Louise does indeed reveal herself warmly in her more than 650 extant letters and numerous writings, which I was privileged to read in Paris and to compare meticulously line by line to the edition published in 1960, which while uncritical;, is faithful to the original.