This essay traces a critique of anti-sentimentalist leftist impersonality in the critically underestimated and best-selling novel The Unpossessed (1934). Tess Slesinger’s satire parodies the deadened affect that results from programmatic refusals of subjectivity and personal life among New York intellectuals who ineffectually conspire to found a radical magazine. Although the novel has typically been read as a roman à clef, its broader target becomes evident when positioned in relation to masculinist orthodoxies of objectivity and scientific materialism that dominated American Marxist magazines in the early 1930s. Pitted against abstraction in particular, Slesinger challenges impersonality’s disembodied imperative, which renders what this article terms “impersons”: waifs “unpossessed” of agency and emotional intensity, and thus unfit not only for collective action but any form of deliberate futurity whatsoever. Slesinger’s intervention suggests a deep affinity between leftist collectivism and modernist individualism, despite their superficial antinomy: according to her, both dangerously extend a suspicion of sentiment into the negation of personhood.