Ruth Barcan Marcus died February 19. She was a towering figure in philosophical logic in the latter half of the 20th century. She initiated the study of quantified modal logic in her 1946 JSL paper, “A functional calculus of first order based on strict implication”. Facing strong opposition from Quine, who thought quantified modal logic was incoherent, her work was only taken up years later. It is now recognized as the seminal contribution that it was.