The martyr sacrifices herself (himself in a few instances) entirely in vain. Or rather not in vain; for she (or he) makes the selfish more selfish, the lazy more lazy, the narrow narrower.
ATTRIBUTION:
Florence Nightingale (18201910), British nurse. Letter, c. 1867, to the scholar Benjamin Jowett. Forever Yours, Florence Nightingale: Selected Letters, ch. 4 (1989).