At the heart of early collecting activities and the development of the science museum is an ethos of collection reaching back to medieval manuscript culture. As Paula Findlen and James J. Bono have explored, the history of museums and the history of book culture share a language and a philosophy; I argue that these shared traits are rooted primarily in the management of physical space – on the page and in the collection cabinet and museum. In the ‘age of the compiler’ (M.B. Parkes) from the thirteenth century on in the middle ages, the assembly of texts in books was highly theorized. The medieval theory of authorship attributed all textual activity to theological – and therefore cosmological – realms. Text for the medievals was quite literally the word of God, the ultimate auctor or author; by extension the management of text on the page was a theological and philosophical activity. For professional bookmakers, especially ecclesiastics, bookmaking work was discussed as two interlocking activities – compilatio and ordinatio. Museums, collector’s cabinets and other structural spaces of material culture actually refer back to earlier codicological models – specifically, the medieval manuscript and its illuminations – and the visual syntax of these images speaks directly to a text-based philosophy of collecting from the middle ages. This paper explores medieval theories of book production as they are seen in early science collecting and museum-making. I will discuss the wider implications of codicological models for scientific cultures and the creation of ‘codicosmology’, the construction of scientific models and ideas of the cosmos underpinned by medieval book theory.