Each week, we select the most interesting Jewish obituary. This week, it’s that of Ruth Barcan Marcus, who died last month at 90. The obituary digs surprisingly deep into Marcus’s achievements as a scholar of quantified modal logic. But perhaps just as memorable is the way she chose a field that was male-dominated, to say the least, and didn’t let that stop her from becoming one of its most revered members, paving the way for other women there and in related fields. Bonus: her father was a typesetter at the Forverts.