[1] Prior to his work in philosophy, Marcus taught mathematics and other subjects at high schools in New York City and Costa Rica.
[1] He received his bachelor of arts in philosophy at Swarthmore College in 1988.
He received his doctorate from the Graduate Center of the City University of New York in 2007,[2] where he wrote his dissertation "Numbers without Science".
[1] He gained tenure in 2016 and was appointed Chair of Philosophy in 2020.
[2][4] In 2020, he won the American Philosophical Association's Prize for Excellence in Philosophy Teaching which "recognizes a philosophy teacher who has had a profound impact on the student learning of philosophy in undergraduate and/or pre-college settings", being cited as an "important scholar of teaching and learning in philosophy" for his summer program and "inventive team-based pedagogies and exemplary scaffolded assignments".