The arbitrary division into lines and pages of the book in its present format, does not correspond at all, with the presentation of ideas. (Otlet, 1911, p. 291)
Most historical explanations of interfaces are technological and start with the computer age. We propose a different approach by focusing on the history of library and information sciences, particularly on the case of Paul Otlet (1868–1944). Otlet's attempts to integrate and distribute knowledge imply the need for interfaces, and his conceptualizations are reminiscent of modern versions of interfaces that are intended to facilitate manual and mechanical data integration and enrichment. Our discussion is based on a selection from the hundreds of images of what we may think of as “interfaces” that Otlet made or commissioned during his life. We examine his designs for interfaces that involve bibliographic cards, that allow data enrichment, his attempts to visualize interfaces between the sciences and between universal and personal classifications, and even his attempts to create interfaces to the world. In particular, we focus on the implications of Otlet's dissection of the organization of the book for the creation of interfaces to a new order of public knowledge. Our view is that the creative ways in which he faces tensions of scalability, representation, and perception of relationships between knowledge objects might be of interest today.