<p>Lev Karsavin’s was unique among his peers. Aside from his place in Lithuania, distal from the Parisian “epicentre” of the twentieth century Russian diaspora <i>intelligentsia</i>, his religious philosophy was distinguished by its stress on <i>vseedinstvo</i> (trans. “all-unity”). In this he was a major inheritor of nineteenth century Russian thought tradition. His interest in personhood, expressed as symphonic personhood, was also seminal to the study of the human person. In this paper, with methodological differences accounted for, parallels are drawn between the subject of personhood in a multidisciplinary light—in particular, Carl Rogers’ person-centred therapy and John Zizioulas’s trinitarian ontology of personhood. Comparisons are also drawn between Karsavin’s notion of personhood and its counterpart “personalism”, common to the Russian Religious Renaissance. Despite the charge of “pantheism”, Karsavin’s notion of personhood is judged as having had seminal significance in the emergent study of personhood itself against the backdrop of the socio-cultural and political conditions of the twentieth century.</p>