This article seeks to decentre the proprietary author in copyright law by attending to some peripheral matters of Immanuel Kant’s periodical essay, ‘On the Wrongfulness of Reprinting’ (1785), as indices of its medial-material conditions of possibility. We consider not only the epitextual background of the German Enlightenment in which the Berlinische Monatsschrift was produced, but also the peritextual specimens of catchwords, signature marks, and various front matter of Kant’s essay. This medial reading suggests the periodical to be deeply involved in the operations of a print machinery preceding the authorial figure, the existence of which perturbs copyright law’s attachment to original authorship.