What pertinence might the philosophy of Jean-Paul Sartre hold for Philip Roth’s brief but provocative contribution to Norman Podhoretz’s Commentary collection, “Jewishness and the Younger Intellectuals: A Symposium” (1961), and for Roth’s attitude to Judaism and ethnic bias generally? The article suggests that ideas advanced in Sartre’s Anti-Semite and Jew (1946) helped Roth shape his symposium essay and, more importantly, his early skepticism about religious affiliation grounded in hatred and chauvinism rather than in living, generative faith. The association of Sartrean ideas — the distinction, in Being and Nothingness (1943), between Being in-itself and Being for-itself and Sartre’s views on anti-Semitism — figures in Roth’s comments on twentieth-century Jewish outlook and in his formulation of “Grossbartism.” This existential mix may owe something, as well, to the Heideggerian state of being “thrown” — insofar as Sartre appropriates the concept to discuss the prospect of being thrown into a trans-cultural state of tolerance, a state that Roth seems to desire for Jew and gentile alike.