I am very sorry to report that Professor Marcus passed away today. She was a wholly sui generis presence in philosophy of the last sixty years: she made seminal contributions to logic, metaphysics and philosophy of language; she rose to the highest levels of the profession at a time when sexist discrimination was utterly rampant; and she was a fearless and indefatigable advocate for the highest standards of intellectual integrity. You may read the tribute to her work by Timothy Williamson (Oxford) here, and her own brief intellectual and professional autobiography here. I will post links to other memorials and additional information soon.
UPDATE: A nice memorial notice from the Yale Daily News.
ANOTHER: Some nice personal remembrances from philosophers here and here. I'll just add a few personal recollections of my own. I corresponded with Ruth regularly from the mid-1990s onwards; our last exchanges were just last year. During the year I taught at Yale (1998-99), I had the pleasure of having lunch with her a couple of times, as well as seeing her often at the legal theory workshops, where her audible 'whispers' about the hair-brained arguments of some of the presenters were always spot on and very funny. Ruth was always a stalwart supporter of the PGR, and gave me much good advice over the years. She has the distinction of being the only person to have ever reprimanded me for being insufficiently candid and direct! And whenever she thought I made a misjudgment, she cetainly let me know (most recently, mentioning on the blog as someone who should be elected to the American Academy of Arts & Sciences someone she deemed absolutely unworthy--that person still hasn't been elected, I hasten to add). I didn't always agree with her, but I always valued her input and her honesty. Academics, alas, tend to be cowards, afraid of their own shadows, but she was the exception that proved the rule.
MORE: Yale's memorial notice.
ANOTHER: From The Economist.
AND FINALLY: The New York Times obituary has appeared, and they did a nice job on it, I thought.