The central notion in Vladimir Aristov’s book is Idem-forma, advanced by the author for the analysis of literary similarities that are not covered by the traditional comparative terms, e. g., contacts or typology. A physicist and a poet, Aristov undertakes the task of scholarly investigation in the style of an essay. The first three of twelve chapters in his book treat the problem theoretically in a broad context of the modern mind. Nine chapters deal with the cases of the ‘identity in the dissimilar,’ suggesting hypotheses of similarity in poetry, prose, and interdisciplinary affinities. The major cases are those where the similarity, no matter how much open to comparative argumentation, allows for viewing two works in a new light, or establishing a plausible typological parallel between them, as it is done for the novels by A. Platonov and W. Faulkner, M. Bulgakov and T. Mann. Idem-forma is an attempt to attract attention to those literary and artistic events that demand an attentive eye towards similar syntactic and rhythmic patterns in poetry, or plots and characters in prose which do not lie on the surface to be related or explained but are supposed to interact in the domain of world literature.